The bora-ene reaction of sulfur dioxide and prop-2-ene-1-boronic esters. New route to sulfoxides
作者:Māris Turks、Adrien K. Lawrence、Pierre Vogel
DOI:10.1016/j.tetlet.2006.02.071
日期:2006.4
A new one-pot synthesis of sulfoxides is presented. It involves the bora-ene reaction of sulfur dioxide and prop-2-ene-1-boronic esters, giving mixed anhydrides of sulfinic and boric acids. The latter react chemoselectively at the sulfur center with Grignard reagents in displacement reactions giving the corresponding prop-2-en-1-ylsulfoxides. Preliminary studies on the chirality transfer of enantiomerically
Chiral boronates—versatile reagents in asymmetric synthesis
作者:Sabine Thormeier、Bertrand Carboni、Dieter E Kaufmann
DOI:10.1016/s0022-328x(02)01323-2
日期:2002.9
The new, axially chiral borates 2, 9, and 11 and boronates 3–6 and 12 are synthesized in good yields. They are representatives of three different structural types. The bicyclic borates 2 and 9 are homochiral propeller compounds; their exclusive formation is used to increase the enantiomerical purity of 1. Especially the borates are efficient Lewis acidic catalysts for stereoselective Diels–Alder reactions