Copper(I)-Catalyzed Formal Carboboration of Alkynes: Synthesis of Tri- and Tetrasubstituted Vinylboronates
摘要:
The first copper-catalyzed formal carboboration of alkynes, in which a C-B bond and a C-C bond are created in a single catalytic cycle, is presented. The reaction proceeds with high regioselectivity and syn-stereoselectivity to form tri- and tetrasubstituted vinylboronic esters from commercially available bis-(pinacolato)diboron. A subsequent cross-coupling reaction gives access to highly substituted alkenes.
Copper(I)-Catalyzed Formal Carboboration of Alkynes: Synthesis of Tri- and Tetrasubstituted Vinylboronates
摘要:
The first copper-catalyzed formal carboboration of alkynes, in which a C-B bond and a C-C bond are created in a single catalytic cycle, is presented. The reaction proceeds with high regioselectivity and syn-stereoselectivity to form tri- and tetrasubstituted vinylboronic esters from commercially available bis-(pinacolato)diboron. A subsequent cross-coupling reaction gives access to highly substituted alkenes.
Stereoselective Synthesis of Trisubstituted Alkenylboron Reagents by Boron-Wittig Reaction of Ketones
作者:Sheila Namirembe、Chenpeng Gao、Ryan P. Wexler、James P. Morken
DOI:10.1021/acs.orglett.9b01663
日期:2019.6.7
Application of the boron-Wittigreaction to ketone electrophiles provides a straightforward route to trisubstituted alkenylboronic esters. With either a pentamethyldiethylenetriamine or trimethyl-1,4,7-triazacyclononane additive, the olefination can occur with very high levels of stereocontrol and in good chemical yield.