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{"title":"Non-Metal-CatalyzednHeterodehydrocoupling of Phosphinesnand Hydrosilanes: Mechanistic Studies of B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>‑Mediated Formation of P–Si Bonds","authors":"Lipeng Wu (49051), Saurabh S. Chitnis (1947028), Haijun Jiao (1400491), Vincent T. Annibale (3862288), Ian Manners (1314384)","doi":"10.1021/jacs.7b09175.s001","DOIUrl":"https://doi.org/10.1021/jacs.7b09175.s001","url":null,"abstract":"Non-metal-catalyzednheterodehydrocoupling of primary and secondarynphosphines (R<sup>1</sup>R<sup>2</sup>PH, R<sup>2</sup> = H or R<sup>1</sup>) with hydrosilanes (R<sup>3</sup>R<sup>4</sup>R<sup>5</sup>SiH, R<sup>4</sup>, R<sup>5</sup> = H or R<sup>3</sup>) to producensynthetically useful silylphosphines (R<sup>1</sup>R<sup>2</sup>P–SiR<sup>3</sup>R<sup>4</sup>R<sup>5</sup>) has been achieved using B­(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> as the catalyst (10 mol %, 100n°C). Kinetic studies demonstrated that the reaction is first-ordernin hydrosilane and B­(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> but zero-ordernin phosphine. Control experiments, DFT calculations, and DOSY NMRnstudies suggest that a R<sup>1</sup>R<sup>2</sup>HP·B­(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> adduct is initially formed and undergoesnpartial dissociation to form an “encounter complex”.nThe latter mediates frustrated Lewis pair type Si–H bond activationnof the silane substrates. We also found that B­(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> catalyzes the homodehydrocoupling of primarynphosphines to form cyclic phosphine rings and the first example ofna non-metal-catalyzed hydrosilylation of P–P bonds to producensilylphosphines (R<sup>1</sup>R<sup>2</sup>P–SiR<sup>3</sup>R<sup>4</sup>R<sup>5</sup>). Moreover, the introduction of PhCN tonthe reactions involving secondary phosphines with hydrosilanes allowednthe heterodehydrocoupling reaction to proceed efficiently under muchnmilder conditions (1.0 mol % B­(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub> at 25 °C). Mechanistic studies, as well as DFT calculations,nrevealed that PhCN plays a key mechanistic role in facilitating thendehydrocoupling reactions rather than simply functioning as H<sub>2</sub>-acceptor.","PeriodicalId":522553,"journal":{"name":"Figshare","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147899228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}