Asymmetric Catalytic Enantio- and Diastereoselective Boron Conjugate Addition Reactions of α-Functionalized α,β-Unsaturated Carbonyl Substrates
作者:Jian-Bo Xie、Siqi Lin、Shuo Qiao、Guigen Li
DOI:10.1021/acs.orglett.6b01998
日期:2016.8.5
established for the asymmetric boron conjugate addition of B2pin2 onto α-functionalized (involving C, N, O, and Cl) α,β-unsaturated carbonyls under mild, neutral conditions involving Cu[(S)-(R)-ppfa]Cl, AgNTf2, and alcohols. The dual additives of AgNTf2 and alcohols were found to play crucial roles for achieving high catalytic activity and enantio- and diastereoselectivity (up to 98% ee and 70:1 dr).
for the asymmetric aldol reaction of chloroacetone. The stereoselective synthesis of vic-halohydrins was accomplished with excellent regioselectivity (>99%) to generate α-chloro-β-hydroxy ketones with high syn selectivity (syn/anti = 16:1) and enantioselectivity (up to 95% ee). aldol reaction - amino acids - asymmetric synthesis - chloroacetone - organocatalysis
升-叔-亮氨酸被认为是为氯丙酮的不对称醛醇缩合反应的有效有机催化剂。vic-卤代醇的立体选择性合成具有出色的区域选择性(> 99%),可生成具有高syn选择性(syn / anti = 16:1)和对映选择性(高达95%ee)的α-氯-β-羟基酮。 Aldol反应-氨基酸-不对称合成-氯丙酮-有机催化
Highly Enantioselective Proline-Catalysed Direct Aldol Reaction of Chloroacetone and Aromatic Aldehydes
作者:Ángel Martínez-Castañeda、Belén Poladura、Humberto Rodríguez-Solla、Carmen Concellón、Vicente del Amo
DOI:10.1002/chem.201103667
日期:2012.4.23
Ready salted proline: The combination of proline and an achiral triazabicyclodecene‐derived guanidinium salt permits, for the first time, the direct aldol reaction of chloroacetone and aromaticaldehydes (see scheme). The resulting chlorohydrins are formed with high regio‐, diastereo‐ and enantioselectivity. This procedure is experimentally simple and green, working without solvent, in test tubes placed