{"title":"使用预制或原位生成的 Co 配合物对苯乙烯进行室温气相氧化或非水马科夫尼科夫水合反应的糖源配体","authors":"","doi":"10.1039/d4cy00522h","DOIUrl":null,"url":null,"abstract":"<div><p>The oxidation of styrenes to acetophenones is an industrially relevant transformation that has been traditionally conducted with the Wacker-type reaction using pure oxygen at high temperature and pressure using Pd–Cu catalysts. Herein, we report a Co(<span>ii</span>) complex of a salen appended <span>l</span>-diaminoribose-derived ligand that is catalytically active for the room temperature, selective aerial oxidation of styrenes to acetophenones. Further, the <em>in situ</em> generated Co(<span>ii</span>) complex (from a mixture of the salen appended <span>l</span>-diaminoribose-derived ligand and a Co(<span>ii</span>) salt) is also found to enable the catalysis. The oxidation is efficiently conducted in the presence of Et<sub>3</sub>SiH as a hydrogen atom transfer (HAT) agent and provides very high isolated yields (71–95%) of the acetophenones. Further, the HAT mediated transformation with NaBH<sub>4</sub> also enables the non-aqueous, Markovnikov hydration of styrenes, providing the corresponding benzylic alcohols, exclusively as a single product in over 72–97% isolated yields <em>via</em> an oxidation–reduction mechanism. The methodologies provided very high exclusive yields of the products and were compatible with various substitutions on the aryl ring of the styrene. Detailed experimental and computational studies revealed a structural feature of the ligand that enabled the facile formation and stabilization of a <em>pseudo</em>-octahedral Co(<span>iii</span>) intermediate that facilitated the oxidation reaction.</p></div>","PeriodicalId":66,"journal":{"name":"Catalysis Science & Technology","volume":null,"pages":null},"PeriodicalIF":4.4000,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"A sugar-derived ligand for room temperature aerial oxidation or non-aqueous Markovnikov hydration of styrenes using a preformed or in situ generated Co complex†\",\"authors\":\"\",\"doi\":\"10.1039/d4cy00522h\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The oxidation of styrenes to acetophenones is an industrially relevant transformation that has been traditionally conducted with the Wacker-type reaction using pure oxygen at high temperature and pressure using Pd–Cu catalysts. Herein, we report a Co(<span>ii</span>) complex of a salen appended <span>l</span>-diaminoribose-derived ligand that is catalytically active for the room temperature, selective aerial oxidation of styrenes to acetophenones. Further, the <em>in situ</em> generated Co(<span>ii</span>) complex (from a mixture of the salen appended <span>l</span>-diaminoribose-derived ligand and a Co(<span>ii</span>) salt) is also found to enable the catalysis. The oxidation is efficiently conducted in the presence of Et<sub>3</sub>SiH as a hydrogen atom transfer (HAT) agent and provides very high isolated yields (71–95%) of the acetophenones. Further, the HAT mediated transformation with NaBH<sub>4</sub> also enables the non-aqueous, Markovnikov hydration of styrenes, providing the corresponding benzylic alcohols, exclusively as a single product in over 72–97% isolated yields <em>via</em> an oxidation–reduction mechanism. The methodologies provided very high exclusive yields of the products and were compatible with various substitutions on the aryl ring of the styrene. Detailed experimental and computational studies revealed a structural feature of the ligand that enabled the facile formation and stabilization of a <em>pseudo</em>-octahedral Co(<span>iii</span>) intermediate that facilitated the oxidation reaction.</p></div>\",\"PeriodicalId\":66,\"journal\":{\"name\":\"Catalysis Science & Technology\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.4000,\"publicationDate\":\"2024-08-12\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Catalysis Science & Technology\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/org/science/article/pii/S2044475324004179\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Catalysis Science & Technology","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/org/science/article/pii/S2044475324004179","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
A sugar-derived ligand for room temperature aerial oxidation or non-aqueous Markovnikov hydration of styrenes using a preformed or in situ generated Co complex†
The oxidation of styrenes to acetophenones is an industrially relevant transformation that has been traditionally conducted with the Wacker-type reaction using pure oxygen at high temperature and pressure using Pd–Cu catalysts. Herein, we report a Co(ii) complex of a salen appended l-diaminoribose-derived ligand that is catalytically active for the room temperature, selective aerial oxidation of styrenes to acetophenones. Further, the in situ generated Co(ii) complex (from a mixture of the salen appended l-diaminoribose-derived ligand and a Co(ii) salt) is also found to enable the catalysis. The oxidation is efficiently conducted in the presence of Et3SiH as a hydrogen atom transfer (HAT) agent and provides very high isolated yields (71–95%) of the acetophenones. Further, the HAT mediated transformation with NaBH4 also enables the non-aqueous, Markovnikov hydration of styrenes, providing the corresponding benzylic alcohols, exclusively as a single product in over 72–97% isolated yields via an oxidation–reduction mechanism. The methodologies provided very high exclusive yields of the products and were compatible with various substitutions on the aryl ring of the styrene. Detailed experimental and computational studies revealed a structural feature of the ligand that enabled the facile formation and stabilization of a pseudo-octahedral Co(iii) intermediate that facilitated the oxidation reaction.
期刊介绍:
A multidisciplinary journal focusing on cutting edge research across all fundamental science and technological aspects of catalysis.
Editor-in-chief: Bert Weckhuysen
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