Noncontact catalysis: Hoʻomaka o ka koho ʻana i ka ethylbenzene oxidation e Au cluster-facilitated cyclooctene epoxidation

Ma ka maʻamau, hana ka catalyst ma ka launa pū ʻana me nā reactants.I loko o kahi ʻōnaehana catalytic nocontact hou (NCCS), he mea waena i hana ʻia e hoʻokahi hopena catalytic ma ke ʻano he mea waena e hiki ai i kahi pane kūʻokoʻa ke hoʻomau.ʻO kekahi laʻana, ʻo ia ke koho ʻana o ka ethylbenzene, ʻaʻole hiki ke loaʻa i mua o nā nanoclusters Au a i ʻole cyclooctene i hoʻoheheʻe ʻia, akā ua hele maʻalahi i ka wā e noho like ai lāua ʻelua.Na Au-hoʻomaka koho epoxidation o cyclooctene hana cyclooctenyl peroxy a me oxy radicals i lawelawe ma ke 'ano he mau intermediaries e hoʻomaka i ka ethylbenzene oxidation.Ua hoʻonui maikaʻi kēia ʻōnaehana hui i ka hopena catalytic o Au.Ua kākoʻo ʻia ke ʻano hana pane e nā kinetics reaction a me nā hoʻokolohua ʻōniʻoniʻo.Hiki i ka NCCS ke hoʻomau i nā hopena like ʻole me ka ʻole o nā kaohi o nā pilina stoichiometric, e hāʻawi ana i nā degere hou o ke kūʻokoʻa i nā kaʻina hana hoʻohuihui hydrocarbon ʻoihana.

Ma ke 'ano ma'amau, ho'opili pololei ka mea ho'opi'i me nā mea ho'ohenehene (pane A) no ka ho'okō 'ana i ka ho'oponopono hou 'ana o ka pilina i kuhikuhi 'ia e ka pane.No ka laʻana, i loko o ka cobalt-catalyzed oxidation o alkylaromatics (1) a i ʻole Au-catalyzed epoxidation o cyclooctene (2), ka mea hoʻoheheʻe e hoʻomaʻamaʻa i ka abstraction o kahi hydrogen atom mai ka hydrocarbon e hoʻomaka i ka hopena.I loko o ka noa radical chain reaction, he catalyst komo i ka catalytic homolytic cleavage o ka nawaliwali paʻa i loko o nā mea hoʻomaka i hoʻohui ʻia a i ʻole e like me nā mea haumia adventitious i ka hui ʻana (1, 3, 4).ʻAʻole pono paha kekahi mau ʻanuʻu i loko o ka hopena catalytic tandem e hoʻopili pololei i ka substrate-catalyst inā hiki ke hoʻololi ʻia o ka substrate e ka huahana i hana ʻia me ka catalytically ma nā ʻanuʻu mua (5-8).Eia naʻe, kaohi ʻia kēia mau ʻano e nā pilina stoichiometric ma waena o nā ʻanuʻu.No ka laʻana, i loko o ka Mukaiyama (ep) oxidation o kahi alkene, ua hoʻololi kekahi catalyst i kahi mea hoʻohaʻahaʻa mōhai i ka pane A, e like me isobutyraldehyde, me ka hoʻokumu ʻana o ka stoichiometric o kahi epoxide (pane B) (9, 10).ʻOiai hiki ke kumu, ʻaʻole mākou ʻike i kahi laʻana e hana ai ka hana o ka catalyst e hana i kahi S intermediate i ka pane A, kahi e lawelawe ai ʻo S ma ke ʻano he intermediary e hoʻomaka a hoʻopaʻa paha i kahi pane ʻē aʻe B ma mua o ke komo ʻana ma ke ʻano he stoichiometric reagent. , ʻoiai ʻaʻole pono ka catalyst no ka pane B (Fig. 1).I loko o ia ʻano, ua hoʻonui ʻia ka mana o ka mea hoʻoheheʻe ma mua o ka hoʻopili ʻana i ka hopena A i ka hopena pū ʻana i ka hopena B akā me ka hoʻopili pololei ʻole ʻana me kāna mau mea hoʻoiho.Ua kapa mākou i kēia ʻano he ʻōnaehana catalytic nocontact (NCCS).I ka NCCS, ʻaʻole i hoʻopaʻa ʻia ka nui o ka hopena o nā hopena A a me B e kekahi pilina stoichiometric ma waena o lākou.He ʻokoʻa kēia me nā pane tandem.I loko o ka ʻoihana, hoʻokau pinepine ka pilina stoichiometric i nā kaohi waiwai ma ke kaʻina hana kemika.ʻO kahi laʻana kaulana ʻo ia ka hana stoichiometric o ka phenol a me ka acetone ma o ka hoʻohemo ʻana o benzene ma o ka cumene hydroperoxide waena ma ke kaʻina cumene (11).

Hoʻopili ka mea hoʻoheheʻe (Cat) i ka pane A (AR ➔ S ➔AP) i mea e pono ai ka S intermediate i ka hoʻomaka ʻana a i ʻole ka hoʻopaʻa ʻana i ka pane ʻana B (BR ➔ BP), ʻoiai ʻaʻole i hoʻopaʻa ʻia ka hopena B e ka catalyst.

Ua loaʻa iā mākou kahi NCCS i ka wā e ʻimi ai i nā waiwai catalytic o nā puʻupuʻu Aun i hoʻoheheʻe ʻia (kahi n i ʻeono a ʻewalu mau ʻātoma) no ka ʻoki ʻia ʻana o ka ethylbenzene (EB).Ua hōʻike mākou i ka hoʻomaka ʻana o ka epoxidation koho o cyclooctene (cC8═) me O2 me ~80% selectivity (2).Ua hoʻokumu ʻia kēia mau pūʻulu i loko o ka Au/SiO2-catalyzed cC8═ epoxidation, a mālama lākou i ko lākou hiki ke hana i ka radical initiator cyclooctene hydroperoxy radical (cC8═OO·) i loko o ka hopena.Hiki ke hōʻiliʻili ʻia nā puʻupuʻu Aun i hoʻoheheʻe ʻia i ka hui ʻana ma hope o ka wehe ʻana o Au/SiO2, a ua hoʻoholo ʻia ko lākou nui awelika me ka hoʻohana ʻana i ka microscopy electron aberration a me ka spectroscopy fluorescence (2).Ma waho aʻe o nā pūʻulu Aun, ua loaʻa i kēia mau hui ʻana ka cyclooctene hydroperoxide (cC8═OOH) a me nā huahana oxidation cyclooctene epoxide, cyclooctenol, a me cyclooctenone.ʻO cC8═OOH ke ʻano hydrogenated paʻa o cC8═OO· a aia ma ka ʻike o 0.2 a 0.5 M ma hope o 40 a 100% cC8═ hoʻololi.Ua kapa ʻia kēia hui ʻana ʻo Au + cC8═OOH-x, kahi o x ka pākēneka cC8═ hoʻololi.ʻOiai ma ka lohi lohi a me ka lōʻihi (> 5 mau hola) manawa hoʻokomo, hiki i ka cC8═ epoxidation hiki ke loaʻa ma ka auto-oxidation me ka ʻole o nā pūʻulu Aun.Ua kapa ʻia nā huila i loaʻa ma ka auto-oxidation me ka ʻole o Au, cC8═OOH-x.I loko o ka NCCS, ʻo ka Aun i hoʻoheheʻe ʻia ʻo ia ka catalyst, ʻo ka epoxidation o cC8═ ʻo ia ka pane A, a ʻo cC8═OO· ʻo ia ka S.

ʻAʻole hiki koke mai ka auto-oxidation o EB.Ma 145°C, 9% wale nō ka hopena i loaʻa no ka EB maʻemaʻe ma lalo o 2.76 MPa O2 (12).Ma lalo o ko mākou kūlana haʻahaʻa loa o 100°C a me ka huʻihuʻi O2 ma 0.1 MPa, ʻaʻohe ʻike ʻike ʻia o ka EB maʻemaʻe no ka liʻiliʻi o 20 mau hola.Ua koi ʻia ka hoʻohui ʻana i kahi mea hoʻomaka radical manuahi no ka hoʻomau ʻana o kēia pane.ʻO ka hoʻomaka me 2,2′-azobisisobutyronitrile (AIBN), kahi mea hoʻomaka radical thermal reactive, i hopena i ka auto-oxidation o EB me ka lōʻihi o ke kaulahao awelika o ~ 3 (fig. S2A).Ua ʻike ʻia kahi kaulahao pōkole (~1) me ka hoʻohana ʻana i ka tert-butyl hydroperoxide liʻiliʻi (fig. S2B), a ʻaʻole liʻiliʻi ka hopena i ʻike ʻia me ka hoʻohana ʻana i ka cumene hydroperoxide liʻiliʻi loa.No laila, ʻaʻole liʻiliʻi ka hopena o ka auto-oxidation o EB i nā hopena hopena i hōʻike ʻia ma lalo nei.

Ua loaʻa ka hoʻoheheʻe ʻana aerobic mau o EB i ka EB hydroperoxide, acetophenone, a me phenylethanol ma ka hoʻohui ʻana iā Au + cC8═OOH-50 i loko o ka hui ʻana o Aun, cC8═OOH, a me cC8═ ʻaʻole i hoʻokō ʻia (Fig. 2, curve 1).E like me ka mea i hōʻike ʻia e nā hoʻokolohua ma lalo nei, ua pāʻani kēia mau ʻāpana ʻekolu i ke kuleana nui i ka hoʻohāhā EB, a ua pili lākou i ka catalyst, S, a me AR i ka ʻōnaehana NCCS i hōʻike ʻia ma Fig. 1.

(i) 7 ml o EB + 3 ml o Au + cC8═OOH-50;(ii) 7 ml o EB + 3 ml o Au + cC8═OOH-50 + 1.2 mmol PPh3;(iii) 7 ml o EB + 3 ml o Au + cC8═OOH-99 + 0.6 mmol PPh3;(iv) 7 ml o EB + 3 ml o cC8═OOH-50;(v) 7 ml o EB + 3 ml o cC8═OOH-50 + 1.5 mmol PPh3.ʻO ka nui o ka PPh3 i hoʻohui ʻia ua hoʻonohonoho ʻia e like me ka nui o ka hydroperoxide titrated (ka wela hopena, 100°C).

Ma lalo o ko mākou mau kūlana, ʻaʻohe mea hoʻohāhā EB aerobic i ʻike ʻia i loko o ka hui ʻana o cC8═ a me EB (ʻo ia hoʻi, me ka ʻole o Cat a i ʻole S).He mea maikaʻi loa ka Triphenylphosphine (PPh3) i ka wehe ʻana i nā hydroperoxide.A Au + cC8═OOH-99 solution, hoʻopau ʻia o cC8═OOH e ka hoʻohui PPh3, loaʻa iā Aun a me cC8═ liʻiliʻi loa, ʻaʻole hiki ke hoʻomaka i ka pane EB ma hope o 2 mau hola (Fig. 2, curve 3), e hōʻike ana ʻo Aun ʻaʻole pono wale nō.Ua hōʻike pū ʻia kēia hopena ʻaʻole hiki i nā huahana ʻē aʻe o ka oxidation cC8═, e like me ka cyclooctene epoxide, cyclooctene alcohol, a i ʻole ketone, ke hoʻomaka i ka hoʻoheheʻe EB.Ma ka hoʻokoʻa ʻana i ka hoʻokolohua ma luna, ʻo ka wehe ʻana o cC8═OOH me PPh3 mai Au + cC8═OOH-50, e waiho ana ma hope o Aun a me cC8═ unreacted, ʻaʻole i hoʻokaʻawale i ka huli ʻana o EB (hoʻohālikelike i nā pihi 1 a me 2, Fig. 2).

ʻO kēia mau pūʻulu ʻikepili ʻekolu i manaʻo i ka synergism ma waena o Aun a me cC8═ unreacted i ka hoʻomaka ʻana o ka EB oxidation.Manaʻo mākou ua hoʻopaʻa ʻo ʻAun i ka hoʻokahe ʻana o cC8═ e hana i cC8═OOH, ʻo ia ka mea nāna i hoʻomaka i ka pane EB.Hiki ke ho'āʻo ʻia kēia ma ka hoʻohālikelike ʻana i ka maikaʻi o ka hoʻomaka ʻana i ka hoʻokahe EB me ka hui ʻana o cC8═OOH a me cC8═ akā me ka ʻole o Aun ma mua a ma hope o ka wehe ʻana o cC8═OOH me PPh3.No ka hoʻohālike maikaʻi ʻana i nā kūlana o nā hoʻokolohua mua, ua hoʻohana mākou i ka hoʻonā cC8═OOH-50 no ka hui ʻana o cC8═OOH a me cC8═ i mea e hana hou ʻia ai kekahi hopena o nā huahana epoxidation cC8═.Ua hōʻike ʻia nā hopena ma ke alo o cC8═OOH-50, ua hoʻokō maikaʻi ʻo EB (Fig. 2, curve 4).Eia nō naʻe, inā ua wehe ʻia ka cC8═OOH e PPh3, ʻaʻohe pane no ka hola mua a hoʻopaʻa ʻia ka hana ma hope (ka pihi 5).Ua kākoʻo hou kēia mau ʻikepili i ke kumu hoʻohālike ʻo ka hana catalytic o Aun e hoʻomau mau i ka cC8═OOH ma o cC8═ oxidation, a ua hoʻomaka ka cC8═OOH i ka pane EB.Ua hoʻokūpaʻa hou ʻia ka hana catalytic o Aun ma ka nānā ʻana i ka piʻi ʻana o nā helu mua o ka oxidation EB i ka nele o cC8═OOH me ka hoʻonui ʻana i ka ʻike ʻana o Aun (fig. S3).

Ua hōʻike ʻia ke kuleana kūʻokoʻa o Aun i kēia NCCS ma ka nānā ʻana iā Co ma ke ʻano he catalyst ʻē aʻe, i koho ʻia no ka mea, ʻo ka cobalt acetate a me ka cobalt cycloalkanecarboxylate (13) nā mea hoʻoikaika ʻenehana no ka hoʻololi ʻana o EB i acetophenone me ka molecular O2, e hana ana ma lalo o nā kūlana koʻikoʻi a koi i ka ka loaʻa ʻana o ka waikawa a me nā ion bromide.Hoʻohana pū ʻia nā Co complexes no ka koho ʻana aerobic EB oxidation ma ke alo o kahi organocatalyst N-hydroxyphthalimide (NHPI) a i ʻole kahi mea hoʻemi kaumaha (14, 15).Eia nō naʻe, ma lalo o kā mākou ʻano hoʻohālikelike, ʻaʻole i loaʻa i ka loaʻa ʻana o Co/ZSM-5 ka hoʻonā ʻana o EB, cC8═, a i ʻole kā lākou hui ʻana no 6 mau hola.ʻO ia hoʻi, ʻaʻole hiki iā Co wale ke hoʻomaka i ka hoʻonā ʻana.Eia naʻe, ma ke alo o Aun a me cC8═, ua hoʻomaʻamaʻa ia i ka hoʻonā ʻana.Ma muli o ke kūlana, cC8═ a EB paha i ʻekolu a ʻelima mau manawa ʻoi aku ka wikiwiki i ka wā i loaʻa ai ʻo Co/ZSM-5, a ua hoʻonui ʻia ka hoʻonui me ka nui o Co/ZSM-5 (papa S2, hoʻokolohua 6 a 8).Ua hoʻololi iki ʻia ka hāʻawi ʻana o ka huahana oxidation EB i mua o Co/ZSM-5.ʻO ka hoʻonui ʻana i ka nui o Co/ZSM-5 i hoʻonui i ka acetophenone yield a, i ka liʻiliʻi liʻiliʻi, phenylethanol yields ma ka lilo o EB hydroperoxide (papa S3, hoʻokolohua 6 a 8), e like me ka mea i hoʻoheheʻe ʻia e Co catalyzed decomposition o EB hydroperoxide i ka acetophenone a me ka phenylethanol a me ka hoʻoheheʻe ʻia o ka mea hope i ka acetophenone.No ka pono, ua hoʻokomo mākou i ka Co/ZSM-5 i kā mākou hui ʻana e hoʻopōkole i ka manawa pane.

ʻO kahi mea ʻokoʻa ma waena o ka NCCS a me nā ʻōnaehana tandem reaction, ʻo ia ka mea ma mua, ʻaʻohe pilina stoichiometric ma waena o nā hopena A a me B (Fig. 1).No ka hōʻoia i ka hopena o kā mākou hopena ma o NCCS, ua hoʻāʻo mākou i ka hopena o ka hoʻololi ʻana i ka ratio o cC8═ i EB ma o ka nānā ʻana i kā lākou pākēneka pane.Hōʻike ka Kiʻi 3 i nā hopena o ka hoʻololi ʻana i ka ʻike cC8═ mua me ka mālama mau ʻana i ka ʻike EB mua a me nā ʻano hopena ʻē aʻe.Hōʻike ka ʻikepili ʻaʻohe pilina stoichiometric paʻa ma waena o nā nui o nā mea hoʻoheheʻe ʻelua i hoʻohālikelike ʻia, e hōʻoia ana ua ʻokoʻa ke ʻano o ka pane ʻana mai ka hoʻolālā tandem reaction maʻamau.ʻO kahi pūʻulu hoʻokolohua like ʻole i hoʻololi ʻia nā koina EB mua aʻo ka hoʻoponopono ʻana i nā ʻāpana ʻē aʻe i hōʻea i ka hopena like.Mai kēia mau ʻikepili, ua helu ʻia nā pākēneka pane mua (Table 1 a me ka papa S2, nā hoʻokolohua 4 a me 5) a hōʻike ʻia he ʻokoʻa like ʻole no cC8═ a me EB.ʻAʻole i kūʻai ʻia nā pākēneka pane ma waena o nā ʻano ʻelua i ka wā e holo wikiwiki ai kekahi, pono e lohi ka ʻē aʻe.Hiki ke hoʻonui like ʻia ka nui o nā pane ʻelua, e like me ka hōʻike ʻana e nā hoʻokolohua 4 a me 5 ma ka pākaukau S2.Manaʻo ʻia kahi hoʻololi ʻana inā hoʻokūkū ʻo EB a me cC8═ no ka pae hoʻohālikelike catalytic like a i ʻole waena.Ua kūlike pū kēia hopena me ka ʻoiaʻiʻo ʻaʻole i loaʻa a liʻiliʻi paha nā hopena like ʻole o EB a me cC8═ i kā lākou hoʻolaha huahana ponoʻī, e like me ka hōʻike ʻana ma ka Papa 1 a me ka papa S3.

He 0.34 M (A), 1.05 M (B), a me 1.75 M (C) ka helu mua cC8═.Ua hoʻohana ʻia ʻo Decane e hana i nā ʻokoʻa o ka nui o ka cC8═ i hoʻohana ʻia.Nā kūlana ʻē aʻe: 32 mg o Co/ZSM5, 100°C.

Ua kūlike kēia mauʻikepili me ka mechanistic scheme i hōʻikeʻia ma ka Fig. 4, kahi i hoʻokūpaʻaʻia ai nā kapuaʻi koʻikoʻi no ka NCCS a ua hōʻikeʻia nā mea pāʻani nui (hōʻikeʻia kahi papahana piha ma ka fig. S8).Ma kēia hana, hoʻomaka nā pūʻulu Aun i ka pōʻaiapuni cC8═ epoxidation ma ka hana ʻana i nā radical cyclooctenyl (I) a me cyclooctene peroxy radical (II).A laila komo kēia mau radical ʻelua i ka cC8═ epoxidation cycle, e like me ka mea i hoʻokumu ʻia ma mua (2, 16).Ke loaʻa ʻo EB, lilo ʻo II i molekele waena a hoʻokuʻu i waena o ka pōʻaiapili epoxidation cC8═ a me ka pōʻai hoʻohāhā EB.Ma ka pōʻaiapuni EB, hana ʻo II me EB e hana i ka radical phenylethyl, i hana koke i kahi radical phenylethyl peroxy radical (III) ma o ka pane ʻana me O2, no ka mea, ua ʻike ʻia he maʻalahi loa (1).ʻO ka hoʻoheheʻe ʻana o ka hydrogen e III e hana i ka phenylethyl hydroperoxide a ma hope o ka acetophenone a me ka phenylethanol.Hiki iā III ke hana wikiwiki me ka cC8═, ka mea i lilo i ala e hoʻopiha ai i ka II i hoʻopau ʻia e ka pōʻaiapuni o ka EB.No laila, ʻaʻole i hui pū ʻia ka hopena oxidation EB me kahi suppression stoichiometric o ka cC8═ epoxidation reaction, a ʻaʻohe "trade-off" i nā helu pane o EB a me cC8═ e like me ka mea i manaʻo ʻia inā ua hoʻokūkū lākou no ka reagent like. a i ʻole he kahua hoʻoikaika catalytic.No ka mea, komo ʻo II i ka ʻanuʻu hoʻomaka ma nā pōʻai hoʻohāhā ʻelua a me ka cC8═ akā ʻaʻole pololei i nā ʻanuʻu hana huahana, ʻaʻole pili kona hoʻopili ʻana i nā hopena ʻelua i ka puʻunaue huahana.

ʻO Cyclooctene peroxy radical (II) ka mea hoʻolaha nui e hoʻomaka i ka hoʻoheheʻe EB.Hiki ke hana hou ʻia ʻo II ma o ka hopena o EB peroxy radical (III) me cC8═.Ma ka ʻaoʻao hema, hoʻomaka nā pūʻulu Aun i ka pōʻaiapili epoxidation cC8═ (ka pōʻai ma ka hema).Hōʻike ka pōʻaiapuni ma ka ʻākau i nā ʻanuʻu no ka EB oxidation.Hōʻike ʻia nā ʻanuʻu kumu nui no ka NCCS.

No ka hōʻoia ʻana i ka hoʻokumu ʻia ʻana o nā intermediates radical transient e like me ka mea i manaʻo ʻia ma ka Fig. loaʻa nā radical manuahi no ka ʻike ʻana me X-band electron paramagnetic resonance (EPR) spectroscopy.Ma ke ʻano he mana, ʻaʻohe radical i hoʻopaʻa ʻia e DMPO i ka hopena o ka acetone a me ka decane me ka C8═ a i ʻole EB (fig. S4-3).I ka hoʻohui ʻia ʻana o DMPO i ka hui ʻana i loko o ka cC8═OOH a me cC8═ (fig. S4-1), ua hoʻohālikelike maikaʻi ʻia ka spectrum EPR e like me ka huina o kahi ʻano paramagnetic ʻokoʻa nui (A ma ke kiʻi, ~86% o ka huina. simulation intensity) a me ʻelua mau ʻano liʻiliʻi (B a me C, ~ 5 a me ~ 9% o ka nui o ka simulation ikaika, kēlā me kēia), e hāʻawi ana i nā hōʻike pololei o ka hoʻokumu radical i ka wā o ka hopena.Ma ke kumu o ka hoʻohālikelike ʻana o nā waiwai hoʻohui hyperfine i nā mea hoʻohui DMPO i ʻike ʻia (papa S1), ua hāʻawi ʻia ka ʻano C i kahi hoʻohui DMPO/ROO•, ʻo ka cyclooctene 3-peroxy radical (II) i hōʻike ʻia ma ke ʻano he mea waena ma waena o nā mea ʻelua. nā hopena (Fig. 4).Hāʻawi ʻia nā ʻano ʻano A a me B i ʻelua mau mea hoʻohui DMPO/RO• ʻokoʻa iki, kahi i kuhikuhi ai ʻo R i kahi moiety hydrocarbon.Hiki iā lākou kekahi o nā ʻano RO• i hōʻike ʻia ma ka Fig. 4 a i ʻole nā ​​alkoxy radical i hana ʻia mai ka DMPO/ROO• hoʻohui i ka palaho [DMPO/ROO• ʻike ʻia nā mea hoʻohui i paʻa ʻole a decompose i ka alkoxy radical adduct pili (17, 18)] a i ʻole ka hui ʻana o nā mea ʻelua.I ka wā i hoʻokomo pū ʻia ai ka EB i ka hui ʻana, ua hoʻohālikelike maikaʻi ʻia ka spectrum EPR i loaʻa me ka hapa nui o nā ʻano A′, i like loa me nā ʻano A (DMPO/RO•), a me nā ʻano ʻelua ʻano liʻiliʻi ʻo B a me C me nā haʻawina liʻiliʻi like. (fig. S4-2 a me ka papa S1).Ma muli o ka hoʻokomo ʻia ʻana o EB i manaʻo ʻia e alakaʻi i ka hoʻokumu ʻia ʻana o nā radical phenylethyl peroxy (III), ʻo ka ʻano A′ he hui pū ʻia paha o RO• i hana ʻia i loko o ka hopena a me nā mea hoʻohui phenylethyl peroxy, a ma hope iho ua pala i ka phenylethyl oxy DMPO hoʻohui.

ʻO ka hoʻohana ʻana i ka EB-d10 ma ke ʻano he reactant a me ka nānā ʻana i ka lepili deuterium i nā huahana cC8═ hiki ke ʻike inā loaʻa ka hopena o EB me nā radical carbon based cC8═.Ua hōʻike ʻia nā hopena o ia hoʻokolohua ʻaʻohe deuterium i hoʻohui ʻia i loko o ka cyclooctene epoxide (fig. S5 a me S6).Ua mālama ʻo Phenylethanol i ka deuterium a pau i loko o ka reactant EB, a ua hoʻololi kekahi o nā deuteron i loko o ka hui methyl o acetophenone, hiki ke loaʻa i ka spectrometer mass.No laila, ʻaʻohe hōʻike o ka hopena ma waena o EB-d10 a me cyclooctenyl radical, e hoʻokomo i ka deuteron i nā huahana cC8═.

Ua hoʻonui ʻia ka hoʻohana ʻana o ka hoʻolālā NCCS e nānā i ka Au + cC8═OOH-100-kōkua aerobic oxidation o 4-methylanisole.Ma muli o ka ikaika o nā paʻa C─H mua ma kēia mole, ua mālama ʻia ka hopena oxy-functionalization ma kahi wela kiʻekiʻe.Hoʻohālikelike ʻia nā helu mua o ka hoʻololi ʻana o 4-methylanisole i 4-anisaldehyde no nā hopena i hoʻomaka ʻia me Aun a me ka hoʻohui cC8═ a i ʻole (cC8═OOH ua wehe ʻia me PPh3).E like me ka EB oxidation, inā ʻaʻohe cC8═ a ʻaʻohe cC8═OOH i loko o ka hui ʻana, ua lohi loa ka nui o ka oxidation mua (fig. S7).I ka hoʻohui ʻia ʻana o cC8═ i ka hui ʻana, ua ʻike ʻia ka hoʻonui ʻia o ka nui o ka oxidation mua.No laila, ua hiki i nā puʻupuʻu Aun ke hoʻohua i ka cC8═OOH mai ka cC8═ i hoʻohui ʻia e hoʻomaka i ka oxidation o 4-methylanisole e like me ka mea i manaʻo ʻia ma NCCS.

I ka hopena, ua hōʻike mākou i ka manaʻo o kahi NCCS.Ke hoʻohana nei i ka oxidation like o cyclooctene a me EB a me cyclooctene a me 4-methylanisole, ua hōʻike ʻia ka NCCS e hiki ai i ka co-oxidation o hydrocarbons me ka ʻole o ka pilina pili stoichiometric o nā kaʻina hana co-oxidation kuʻuna.Hāʻawi kēia i kahi kūʻokoʻa i loaʻa ʻole ma mua o ka hana ʻoihana e like me ke kaʻina hana ʻoihana ʻaʻole i hoʻopaʻa hou ʻia e ka pono o nā mākeke maikaʻi no nā coproducts i hana ʻia i nā huina stoichiometric.

ʻO nā kumu a me ka maʻemaʻe o nā kemika i hoʻohana ʻia penei: HAuCl4•3H2O (≥99.9% trace metals basis, Sigma-Aldrich), fumed silica (CAB-O-SIL90, Cabot Corporation), ethylenediamine (≥99% ReagentPlus, Sigma-Aldrich) , ethanol (200 grade, Decon Labs), cobalt(II) nitrate hexahydrate (≥98%, Sigma-Aldrich), Nano H-ZSM-5 (P-26, ACS Material), decane (≥99% ReagentPlus, Sigma- Aldrich), dodecane (≥99% ReagentPlus, Sigma-Aldrich), cis-cyclooctene (95%, Alfa Aesar), EB (99.8% anhydrous, Sigma-Aldrich), EB-d10 (99 atomic % D, Sigma-Aldrich) , 4-methylanisole (99%, Sigma-Aldrich), acetophenone (99% ReagentPlus, Sigma-Aldrich), 1-phenylethanol (98%, Sigma-Aldrich), hydrogen peroxide (30% aqueous solution, Fisher Chemical), potassium hydroxide (Reagent grade, 90%, Sigma-Aldrich), sodium sulfate (Food Chemical Codex/United States Pharmacopeia-grade, Fisher Chemical), tetrahydrofuran (>99%, Sigma-Aldrich), tert-butyl hydroperoxide (~ 5.5 M ma decane , Sigma-Aldrich), PPh3 (> 98.5%, Sigma-Aldrich), d-chloroform (99.8 atomic % D, Sigma-Aldrich), HCl (38% w/w, Fisher Chemical), HNO3 (68 a 70% w /w, Fisher Chemical), EM Quant peroxide nā ʻāpana hoʻāʻo, a me ka kānana syringe (polyvinylidene difluoride membrane, 0.25 mm/0.2 μm, Acrodisc).

Au/SiO2.Ua hoʻomākaukau ʻia ka silica-kākoʻo nanoparticle catalyst me Au (en) 2Cl3 precursor e like me ke ʻano i kūkulu ʻia e Zhu et al.(19) a hoʻololi ʻia e Qian et al.(2).No ka kikoʻī hou aku, ua hoʻomākaukau ʻia kahi solution Au(III) chloride trihydrate ma ka hoʻoheheʻe ʻana i 0.5 g o HAuCl4•3H2O i loko o kahi hui ʻana he 10 ml o ka ethanol a me 2 ml wai.Ma hope o ka hana ʻana i ka hopena homogeneous, ua hoʻohui ʻia ka 0.23 ml o ka ethylenediamine (en = ethylenediamine) i ka hopena dropwise e hana i ka Au(III) ethylenediamine chloride [Au(en)2Cl3] ma o ka hoʻololi ligand.Ua hōʻiliʻili ʻia ka Au(en)2Cl3 i hana ʻia e ka kānana a holoi ʻia me 300 ml o ka ethanol.No ka waiho ʻana iā Au ma luna o ke kākoʻo silica, ua hoʻomākaukau ʻia kahi wai wai 4.2 mM Au(en)2Cl3 ma ka hoʻoheheʻe ʻana i 46.3 mg o Au(en)2Cl3 i loko o 26 ml o ka wai deionized (DDI).Ua mālama ʻia ka hopena i hana ʻia ma 40 ° C i loko o kahi ʻauʻau aila.A laila, hoʻohui ʻia ka 1 g o ka silica fumed i ka hopena preheated i ka wā e hoʻoulu ai.I ka manawa i hoʻokomo ʻia ai nā kākoʻo silica a pau i loko o ka hopena, ua wehe ʻia ka hui ʻana mai ka ʻauʻau aila a hoʻomaha ʻia i ka lumi wela.Ma ka hoʻololi ʻana i ka pH o ka hui ʻana i 9 me ka hoʻohui dropwise o 0.75 M en aqueous solution, ua loaʻa kahi adsorption ʻoi aku ka maikaʻi o nā paʻakikī gula cationic i ka ʻili i hoʻopiʻi ʻia.Ma hope o ka hoʻouluʻana no 2 mau hola i ka mahana wela, ua kānanaʻia ka huiʻana a holoiʻia me 500 ml o ka wai DDI.No ka wehe ʻana i nā koena makemake ʻole (Cl, en, nā haumia ʻē aʻe), ua hoʻopuehu hou ʻia ka keke kānana i 200 ml o ka wai DDI ma 40 ° C.ʻO ka hope, ua hōʻiliʻili ʻia ka Au/SiO2 e like me ka kānana a holoi ʻia me kahi 500 ml o ka wai DDI a maloʻo i ka ea i ka pō.Ua lawe ʻia ka helu ʻana o nā nanoparticles gula i kākoʻo ʻia i ka silica i loko o kahi pahu U ma lalo o ke kahe O2/O3 (~ 300 ml/min) me ka wikiwiki o 0.12°C/min a hiki i 150°C.Mālama ʻia ka catalyst i loko o ka pōʻeleʻele ma 5 ° C.ʻO ka hoʻouka gula, e like me ka helu ʻia e ka inductively coupled plasma optical emission spectrometry, ʻo ia ka 1.2 paona % (wt%), a ʻo ka awelika o ka nui o ke kala gula i ana ʻia e ka scanning transmission electron microscopy (STEM) ma kahi o 2 nm.

Co/ZSM-5.Nano H-ZSM-5 ua calcined i loko o ka U-tube ma lalo o O2/O3 kahe (~ 300 ml / min) me ka ramping rate o 2°C/min a hiki i 200°C a paa ma 200°C no 1 hola e wehe. koena templates.Ua hoʻomākaukau ʻia ʻo Co/ZSM-5 e ka pulu hoʻomaka.No ka laʻana, ua hoʻomākaukau ʻia kahi 5 wt % loading Co/ZSM-5 ma ka hoʻohui ʻana i kahi solution 0.72 M cobalt (II) nitrate [250 mg o cobalt(II) nitrate hexahydrate i 1.2 ml o ka wai DDI] i 1 g nano H- ZSM-5 oiai e hoohuli akahele ana i ka bea.Ua hoʻomaloʻo ʻia ka slurry ma lalo o ke kukui, a ua hana ʻia kahi pauka ʻulaʻula like ʻole.Hoʻokomo ʻia ka pauka i hana ʻia i loko o kahi paipu calcination pololei a hoʻomaʻemaʻe ʻia ma lalo o ke kahe argon (100 ml / min) no 1 hola e hōʻemi i ka haʻahaʻa.ʻO ka catalyst i hoʻomākaukau ʻia a laila calcined ma lalo o ke kahe o ka oxygen (60 ml / min) me ka wikiwiki o 10 ° C / min a 450 ° (paʻa ma 250 ° C, 350 ° C, a me 450 ° C no 1 hola i kēlā me kēia) .Loaʻa i ka Co/ZSM-5 ka hoʻouka ʻana o ka cobalt o 5 wt%.ʻElua mau ukana ʻē aʻe, 3 a me 7 wt%, ua mākaukau pū.Ua hōʻike ʻia nā catalysts ʻekolu e ka hoʻemi ʻana i ka mahana-programmed H2, ka ʻokoʻa x-ray, ka spectroscopy photoelectron x-ray, a me ka spectroscopy ʻike ʻia ultraviolet.

Au-i loko o ka kānana.ʻO ka filtrate i loaʻa i ka Au (Au + cC8═OOH-x) ma kahi i hana ʻia mai Au/SiO2-catalyzed cC8═ epoxidation reaction e like me ke kaʻina hana i kūkulu ʻia e Qian et al.(2) Ma mua o ka pane ʻana, ua hoʻomaʻemaʻe ʻia ka cC8═ no ka wehe ʻana i ka stabilizer i hoʻohui ʻia.Ma keʻano laulā, ua hoʻohui ʻia he 50 ml o 3 M potassium hydroxide (KOH) i 50 ml o cC8═ i loko o kahi pahu.Ma hope o ka hui ʻana a me ka hoʻoulu ʻana ikaika, ʻohi ʻia ka papa organik ma ka hoʻokaʻawale ʻana.Ua hana hou ʻia kēia kaʻina hana me kahi 50 ml o 3 M KOH a me ʻelua mau 50 ml wai DDI.Hoʻomaloʻo ʻia ka cC8═ me ka sodium sulfate i ka pō.No ka wehe loa ʻana i ka stabilizer, ua hoʻoheheʻe ʻia ka cC8═ maloʻo i loko o kahi ʻauʻau aila ma kahi o 180 ° C, a ua hōʻiliʻili ʻia ka hakina i puka mai ma 145 ° C.Hoʻomaʻemaʻe ʻia ka cC8═ (10 ml) a me ka decane (1 ml) i hui pū ʻia i loko o kahi reactor i loaʻa 80 mg o ka mea hoʻoheheʻe Au/SiO2 i ʻōlelo ʻia.Ua mālama ʻia ka hopena epoxidation cC8═ ma lalo o kahi kahe oxygen (30 ml / min) ma 100 ° C, a nānā ʻia ka hoʻololi ʻana e GC.Ke hiki i ka huli ʻana i makemake ʻia, ua hōʻiliʻili ʻia ka hui ʻana a ua wehe ʻia ka catalyst paʻa e ka kānana wela me ka hoʻohana ʻana i kahi kānana syringe.ʻO ka typical solubilized Au kuʻina i hoʻoholo 'ia e inductively i hui pūʻia plasma nuipa spectrometry ma kahi o 80 ng/ml, a me ka Au puʻupuʻu nui i hoʻoholo 'ia e ka fluorescence spectroscopy a me ka aberration-hoʻoponopono electron microscopy mai Au nā mana a hiki i ~0.7 nm.Ua hoʻomākaukau like ʻia ka cC8═OOH-x me ka hoʻohana ʻole ʻana i ka mea hoʻoheheʻe Au/SiO2.Loaʻa nā ʻāpana Au + cC8═OOH-x a me cC8═OOH-x i nā huahana oxidation cC8═, e komo pū ana me ka cyclooctene oxide, cyclooctene 3-hydroperoxide, 2-cycloocten-1-ol, 2-cycloocten-1-one, a me nā huina. o 1,2-cyclooctanediol.

Kaʻina hana maʻamau.Ua alakaʻi ʻia nā ʻano hoʻoheheʻe EB i ka pōʻeleʻele i loko o kahi reactor cylindrical ʻokoʻa ʻekolu i hoʻolako ʻia me kahi paipu disperser aniani frit maikaʻi (Chemglass Life Sciences) a me kahi condenser i mālama ʻia ma −10°C.Ma ka hopena maʻamau, ua hoʻouka ʻia ka 7 ml o EB, 1 ml o decane, a me 3 ml o ka kānana (Au + cC8═OOH-x a i ʻole cC8═OOH-x) i loko o ka reactor me kahi mea hoʻoheheʻe mākia i uhi ʻia me Teflon.Inā hoʻohana ʻia, ua hoʻohui ʻia ka 32 mg o 5% Co/ZSM-5, ke ʻole i kuhikuhi ʻia.Ma hope o ka hui ʻana o ka hoʻonohonoho ʻana, ua hoʻopaʻa ʻia ka hui ʻana ma lalo o ke kahe N2 no 20 min i loko o kahi ʻauʻau aila preheated.Ke hoʻopaʻa ʻia ka mahana o ka condenser a me ka ʻauʻau aila, ua hāʻawi ʻia kahi kahe O2 mau ma 30 ml / min.Lawe ʻia ka hui ʻana (0.1 ml) i nā manawa like ʻole no ka nānā ʻana (ua hoʻohana ʻia ke kānana syringe i ka wā i komo ai nā catalysts paʻa), hoʻoheheʻe ʻia i 0.7 ml o d-chloroform, a nānā ʻia e 1H nuclear magnetic resonance (NMR).

ʻIke huahana a me ka helu.Ua hoʻoheheʻe ʻia nā ʻāpana o ka hui ʻana me ka tetrahydrofuran a nānā ʻia e ke kinoea chromatography-mass spectrometry (GC-MS; Agilent GC-7890A, MS-5975).No ka pane EB, ua ʻike ʻia ʻo acetophenone a me 1-phenylethanol nā huahana nui.Ua hoʻohana ʻia ʻo 1H-NMR a me 13C-NMR (400 MHz Agilent DD2-MR400 system) e hōʻoia hou i ka ʻike huahana.ʻO 1-Phenylethyl hydroperoxide, ʻaʻole i ʻike ʻia e GC-MS ma muli o kona paʻa ʻole ʻana o ka wela, ua ʻike ʻia e NMR he huahana nui ʻē aʻe.Ua helu ʻia nā huahana ʻekolu e 1H-NMR me ka hoʻohana ʻana i ka decane e like me ke kūlana kūloko (fig. S1).Hoʻokaʻawale ʻia ka poho evaporative a hoʻohana ʻia no ka hoʻoponopono ʻana i nā ʻano huahana.Ma hope o ka hoʻoponopono ʻana i nā poho evaporative, ʻaʻole i ʻike ʻia ke kaulike kalapona no ka pane EB.No ka hopena cyclooctene, cyclooctene oxide, cyclooctane-1,2-diol, 2-cycloocten-1-ol, a me 2-cycloocten-1-one ua helu ʻia e GC.ʻAʻole paʻa a decomposed ʻo Cyclooctene 3-hydroperoxide i ke kolamu GC a no laila ʻaʻole i ʻike ʻia.Aia ma kahi o 10% ka poho kalapona i ka hoʻololi piha ʻana ʻoiai ma hope o ka uku ʻana i ka nalowale evaporative, hiki ke wehewehe ʻia e ka hoʻokumu ʻana o nā huahana i ʻike ʻole ʻia.

Hoʻololi a me ka helu koho.Ua hoʻohana ʻia ʻo GC a i ʻole NMR wahi ratio o ka mole o ka hoihoi i ka decane maʻamau kūloko e helu i ka hoʻololi ʻana a me ke koho.ʻOiai ua hoʻohana ʻia kahi condenser hoʻoluʻu, pono ia e hoʻopaʻi i ka nalowale evaporative ma muli o ke kiʻekiʻe o ka wela o ka hopena a me ka manawa hoʻokō lōʻihi.Loaʻa nā ʻōkuhi hoʻoponopono evaporative no nā EB a me cC8═ ma lalo o ke kahe o ka nitrogen a maʻamau i ka ratio o EB/decane a i ʻole cC8═/decane.No ka mea, he mau wahi paila like ko EB a me cC8═, ʻo nā kumu hoʻoponopono maʻamau i loaʻa he 0.0044 (ua hoʻemi ʻia ka lakio maʻamau i kēlā me kēia hola).

Ka helu o ka hydroperoxide.Ua helu ʻia ka neʻe ʻana o ka hydroperoxide e nā ʻano titration ʻelua:

1) Triphenylphosphine (PPh3) titration.Ua hoʻohana ʻia ʻo PPh3 (0.1 M i EB) no ka hoʻokaʻawale ʻana i nā mea hoʻohālike hydroperoxide ʻike ʻole ʻia, a ʻike ʻia ka helu hope me kahi ʻāpana hoʻāʻo EM Quant peroxide.Ua hoʻohana ʻia ʻo 31P-NMR e hōʻoia i ka hoʻopau piha ʻana o nā ʻano hydroperoxide.

2) Iodometric titration.Ua hui pū ʻia ka laʻana (0.2 ml) me 1 ml o CHCl3/acetic acid (v/v = 1:2) a me 6 ml o 1 M KI solution.Ua hoʻoulu ʻia ka hui ʻana i loko o ka pōʻeleʻele no 2 mau hola a laila titrated me 0.005 M Na2S2O3 i mua o kekahi mau kulu o ka hopena starch.Loaʻa ka hopena i ka wā i lilo ʻole ai ka hui ʻana.

Ua kūlike nā ʻano ʻelua i loko;akā naʻe, ʻokoʻa kā lākou hopena i ka 5 a 10%.Ma muli o ka hana ʻia ʻana o ka Au + cC8═OOH-x a me cC8═OOH-x i hoʻohana ʻia ma kēia papahana ma o cC8═OOH-i hoʻomaka ʻia ka hoʻohāhā ʻana, ʻokoʻa ka manaʻo hydroperoxide mai kēlā me kēia pūʻulu akā aia mau i loko o ka laulā 0.2 a 0.5 M no ka hoʻomākaukau hou. cC8═OOH-40 to cC8═OOH-100 samples.Ua emi mālie ka ʻike hydroperoxide me ka manawa o ka mālama ʻana.

EPR spin trap hoʻokolohua.Ua hoʻohui ʻia ʻo DMPO (23 μl) i ka 1 ml o ka hāpana e hiki i kahi manaʻo DMPO o 0.2 M, a ua hoʻohui ʻia ʻo 20 mg o Co/ZSM-5 i ka hui ʻana o ka hāpana i loko o kahi pahu hoʻāʻo.Ua sonicated ka hui 'ana no ka 1 min e hoʻokuʻu i ka catalyst, a ua ukali ia e ka wela ma 60 ° C no ~ 10 min.Ua hoʻoili ʻia kahi ʻāpana o ka hui ʻana i loko o kahi paipu capillary borosilicate poepoe (1.50 i loko o ke anawaena × 1.80 waho anawaena, Wale Apparatus), i hoʻopaʻa ʻia ma kekahi ʻaoʻao—a laila ua hoʻokomo ʻia kēia paipu i loko o kahi pahu Wilmad quartz X-band EPR ( Sigma-Aldrich).Ua paʻa ka hāpana ma ka hoʻokomo ʻana i ka paipu EPR i loko o ka wai N2.Ma mua koke o ke ana ʻana i ka spectra EPR, ua hoʻoheheʻe ʻia ka hāpana.Ua hana ʻia nā ana ʻana o ka hawewe hoʻomau (CW) X-band EPR ma ka wela lumi ma kahi spectrometer Varian E-4 i hoʻololi ʻia me ka manamana lima Dewar.

Hoʻokolohua hōʻailona isotopic.Ua hoʻohana ʻia ʻo Deuterated EB (d10-EB) i kahi hoʻokolohua o ka hui ʻana o 6 ml o cC8═OOH-45, 5 ml o d10-EB, 1 ml decane, a me 60 mg o Co-ZSM-5 (7%). , ma 120°C, me 6 ml o cC8═OOH-45, 5 ml o EB-d10, a me 1 ml o dodecane.No ka uku ʻana i ka emi ʻana o ka pane ʻana ma muli o ka hopena isotope kinetic, ua lawe ʻia ka co-oxidation ma kahi kiʻekiʻe o 120 ° C.Lawe ʻia nā Aliquots o ka laʻana ma mua a ma hope o 24 mau hola o ka pane ʻana a nānā ʻia e 2H-NMR a me GC-MS.

Ua hōʻike ka spectrum 2H-NMR (fig. S5, spectrum 2) i kekahi mau piko hou ma hope o ka pane ʻana, ʻaʻole i loaʻa ma mua o ka pane ʻana, ma δ1.50, δ1.58, δ4.94, δ7.42 a i δ7.72, a me δ8.04 .Ma muli o ka emi ʻana o ka J-coupling mau a me ka naʻau o 2H-NMR, ʻaʻole i hoʻoholo ʻia nā ʻano hoʻokaʻawale.ʻO nā piko ma δ8.04 a me δ7.42 i δ7.72 i hāʻawi ʻia i nā deuterons o ke apo ʻala o ka acetophenone;ua hāʻawi ʻia nā piko ma δ1.50 a me δ4.94 i ka methyl a me benzylic deuteron o 1-phenylethanol, kēlā me kēia;a ʻo ka piko ma δ1.58 i hāʻawi ʻia i ka deuteron ma D2O i hana ʻia mai ka decomposition hydroperoxide.ʻAʻohe deuteron i loaʻa i pili me nā huahana o ka cyclooctene epoxidation, a ʻo ka hoʻokumu ʻana o ka wai deuterated i hōʻike ʻia ʻo nā mea lawe kaulahao radical nui i ka hopena co-oxidation he peroxy a me ka alkoxy.

Hōʻike ʻia ka spectra GC-MS o nā huahana ma ka fig.S6.ʻO Acetophenone-d8 (m / e 128, hoʻopau piha, fig. S6A, m / e 127 a me 126) ua nānāʻia.Mai ke kumu hoʻohālike, ua hoʻololi ʻia nā HD āpau ma ke kūlana methyl.Eia kekahi, ʻo 1-phenylethanol-d9 (m/e 131) (fig. S6B) wale nō nā huahana deuterated i ʻike ʻia.ʻAʻohe deuterium i loaʻa i loko o ka cyclooctene oxide (fig. S6C), ka hua nui loa mai ka cyclooctene epoxidation.Hiki ke hana ʻia ka 1-Phenylethanol-d9 mai ka hopena o ka radical phenylethoxy me ka cyclooctene.

Loaʻa nā mea hoʻohui no kēia ʻatikala ma http://advances.sciencemag.org/cgi/content/full/6/5/eaax6637/DC1

Fig. S5.2H-NMR ma mua (spectrum 1, ʻulaʻula) a ma hope (spectrum 2, ʻōmaʻomaʻo) 24-hola co-oxidation pane.

Kii S7.Hoʻohālikelike i nā hoʻololi mua o 4-methyl anisole i hoʻomaka me ka hoʻohana ʻana iā Au + cC8═OOH-100, me ka wehe ʻana o cC8═OOH.

He ʻatikala wehe ʻia kēia i hāʻawi ʻia ma lalo o nā ʻōlelo o ka laikini Creative Commons Attribution-NonCommercial, ka mea e ʻae ai i ka hoʻohana ʻana, ka hoʻolaha ʻana, a me ka hana hou ʻana ma nā ʻano mea like ʻole, inā ʻaʻole no ka pono ʻoihana ka hopena o ka hoʻohana ʻana a inā pono ka hana kumu. haʻi ʻia.

MANAʻO: Ke noi wale nei mākou i kāu leka uila i ʻike ka mea āu e paipai nei i ka ʻaoʻao ua makemake ʻoe e ʻike lākou, ʻaʻole ia he leka uila.ʻAʻole mākou e hopu i kahi leka uila.

Na Anyang Peng, Mayfair C. Kung, Robert RO Brydon, Matthew O. Ross, Linping Qian, Linda J. Broadbelt, Harold H. Kung

I loko o kahi ʻōnaehana catalytic nocontact, nā mea hoʻopili i loaʻa mai ka Au-catalyzed cyclooctene epoxidation hopena ethylbenzene oxidation.

Na Anyang Peng, Mayfair C. Kung, Robert RO Brydon, Matthew O. Ross, Linping Qian, Linda J. Broadbelt, Harold H. Kung

I loko o kahi ʻōnaehana catalytic nocontact, nā mea hoʻopili i loaʻa mai ka Au-catalyzed cyclooctene epoxidation hopena ethylbenzene oxidation.

© 2020 ʻAhahui ʻAmelika no ka holomua o ka ʻepekema.Ua mālama ʻia nā kuleana āpau.He hoa pili ʻo AAAS no HINARI, AGORA, OARE, CHORUS, CLOCKSS, CrossRef a me COUNTER.Science Advances ISSN 2375-2548.


Ka manawa hoʻouna: Feb-19-2020