Department of Chemistry, Shenzhen Key Laboratory of Full Spectral Solar Electricity Generation (FSSEG), Southern University of Science and Technology (SUSTech), China.
Angew Chem Int Ed Engl. 2018 Mar 1;57(10):2677-2681. doi: 10.1002/anie.201712693. Epub 2018 Feb 9.
Cross-hydroalkenylation of a vinyl ether (1) with an α-olefin (2) was first achieved by a set of [NHC-Ni(allyl)]BAr (NHC=N-heterocyclic carbene) catalysts. Both 1,2- and 1,3-disubstituted allyl ethers were obtained, highly selectively, by using NHCs of different sizes. In contrast, the chemoselectivity (i.e., 1 as acceptor and 2 as donor) was controlled mostly by electronic effects through the catalyst-substrate interaction. Sterically bulkier alkenes (2) were used as preferred donors compared to smaller alkenes. This electronic effect also served as a basis for the first tail-to-head cross-hydroalkenylations of 1 with either a vinyl silane or boronic ester.
乙烯基醚（1）与α-烯烃（2）的交叉烯丙基化反应首次通过一组[NHC-Ni(allyl)]BAr（NHC=N-杂环卡宾）催化剂实现。通过使用不同大小的 NHC，可以高度选择性地获得 1,2-和 1,3-二取代的烯丙基醚。相比之下，化学选择性（即 1 作为受体，2 作为供体）主要通过催化剂-底物相互作用的电子效应来控制。与较小的烯烃相比，空间位阻较大的烯烃（2）被用作更优选的供体。这种电子效应也为乙烯基硅烷或硼酸酯与 1 的首次尾对尾交叉烯丙基化奠定了基础。
