One, two, three, four: A copper(I)–phosphine complex catalyzes the diborylation of alkynes and arynes, and the tri‐ or tetraborylation of propargyl ethers (see scheme; pin=pinacolato). In the latter cases, the CO bond(s) as well as the CC bond are borylated in one pot. Furthermore, a diborylation product serves as an intermediate in the efficient synthesis of ortho‐terphenyls with pharmacological
Mixed Diboration of Alkynes Catalyzed by LiOH: Regio- and Stereoselective Synthesis of <i>cis-</i>1,2-Diborylalkenes
作者:Sihan Peng、Guixia Liu、Zheng Huang
DOI:10.1021/acs.orglett.8b02830
日期:2018.12.7
A diboration of terminal alkynes with an unsymmetrical diboron reagent pinBBdan has been achieved using LiOH as the catalyst in the presence of stoichiometric amounts of MeOH, affording 1,2-diborylalkenes with different boryl groups. The reaction proceeds in a highly regio- and stereoselective manner through cis-addition of pinBBdan to the C–C triple bond, with the Bdan moiety being incorporated at