使用苄基和叔丁基硫醇作为以硫为中心的亲核试剂,已经完成了对α,β-不饱和酮的高对映选择性有机催化磺胺-迈克尔加成反应。从多种烯酮中以高收率和良好至优异的立体控制(高达96%ee)获得光学活性产品。这些研究的核心是衍生自9-氨基-(9-脱氧)-表氢对苯二酚和D - N - Boc-苯基甘氨酸的催化伯胺盐A的使用,其中阳离子和阴离子均为手性,对烯酮的亚胺离子催化具有高反应活性和选择性。
Asymmetric Michael reactions of thiols with enones were catalyzed by a Sc(OTf)3–chiral bipyridine complex at room temperature in water without using any organic solvents, to afford the desired sulfides in high yields with high enantioselectivities.
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.
We report the first asymmetric sulfa-Michael addition (SMA) reactions using chiral N-heterocycliccarbene (NHC) as a non-covalent organocatalyst. We demonstrate that a triazolium salt derived NHC functions as an excellent...