Asymmetric Michael reactions and enantioselective protonations between enones and thiols were catalyzed by a Sc(OTf)3–chiral 2,2′-bipyridine complex in water. The remarkable governing of the enantioselectivity for simple introduction of protons despite their abnormally high mobility in water may provide us with new synthetic opportunities as well as significant chemical advances.
A Bifunctional Cinchona Alkaloid-Squaramide Catalyst for the Highly Enantioselective Conjugate Addition of Thiols to trans-Chalcones
作者:Le Dai、Su-Xi Wang、Fen-Er Chen
DOI:10.1002/adsc.201000334
日期:2010.9.10
A chiral squaramide catalysts‐promoted asymmetric sulfa‐Michael conjugated addition of thiols to trans‐chalcones is presented. Moderate to excellent yields and high enantioselectivities (up to 99% ee) were achieved under mild conditions.