Contra-Thermodynamic, Photocatalytic <i>E</i>
→<i>Z</i>
Isomerization of Styrenyl Boron Species: Vectors to Facilitate Exploration of Two-Dimensional Chemical Space
作者:John J. Molloy、Jan B. Metternich、Constantin G. Daniliuc、Allan J. B. Watson、Ryan Gilmour
DOI:10.1002/anie.201800286
日期:2018.3.12
Designing strategies to access stereodefined olefinic organoboron species is an important synthetic challenge. Despite significant advances, there is a striking paucity of routes to Z‐α‐substituted styrenyl organoborons. Herein, this strategic imbalance is redressed by exploiting the polarity of the C(sp2)−B bond to activate the neighboring π system, thus enabling a mild, traceless photocatalytic isomerization
Copper(I)-Catalyzed Formal Carboboration of Alkynes: Synthesis of Tri- and Tetrasubstituted Vinylboronates
作者:Ricardo Alfaro、Alejandro Parra、José Alemán、José Luis García Ruano、Mariola Tortosa
DOI:10.1021/ja307670k
日期:2012.9.19
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.