Department of Medicinal Chemistry, University of Kansas, Lawrence, Kansas 66047, United States.
Department of Chemistry, Tulane University, New Orleans, Louisiana 70118, United States.
J Org Chem. 2022 Aug 19;87(16):11237-11252. doi: 10.1021/acs.joc.2c01170. Epub 2022 Jul 28.
We demonstrate that di--butylsilanols are competent nucleophiles for the intramolecular interception of palladium π-allyl species. In these reactions, allyl ethyl carbonates are the best precursors for the formation of palladium π-allyl intermediates, and [(Cinnamyl)PdCl]/BINAP is superior to other Pd salt/ligand framework combinations. Our optimized protocol is compatible with a variety of silanol substrates. Importantly, the cyclization is perfectly stereospecific, proceeding via an - mechanism, which stands in contrast to reported analogous reactions of alcohols and phenols, known to proceed via an - mechanism. The alkenes in the product dioxasilinanes serve as blank slates for further functionalization.
我们证明二丁基硅醇是用于钯π-烯丙基物种的分子内拦截的有效亲核试剂。在这些反应中，烯丙基碳酸乙酯是形成钯π-烯丙基中间体的最佳前体，[(肉桂基)PdCl]/BINAP 优于其他 Pd 盐/配体骨架组合。我们的优化方案与各种硅醇底物兼容。重要的是，环化反应具有完美的立体特异性，通过 - 机制进行，与报道的醇和酚的类似反应形成对比，后者已知通过 - 机制进行。产物二氧杂硅烷中的烯烃可作为进一步官能化的空白模板。
