Oxotitanium complexes useful as asymmetric reaction catalysts particularly for producing beta-hydroxy ketones or alpha-hydroxy carboxylic acid esters
申请人:Takasago International Corporation
公开号:EP0676404A2
公开(公告)日:1995-10-11
A novel oxotitanium complex represented by general formula (I) is disclosed :
wherein R1 and R2 may be hydrogen, lower alkyl, lower alkoxy, halogen, phenyl, substituted phenyl, trialkylsilyl, monoalkyldiphenylsilyl, dialkylmonophenylsilyl, triphenylsilyl, substituted triphenylsilyl, or lower alkoxycarbonyl ; R1 and R2 may be bonded to form a hydrocarbon ring with the ring carbon atoms ; R3 and R4 may be different and each represents hydrogen, lower alkyl, lower alkoxy, benzoyl, benzenesulfonyl, or halogen ; R3 and R4 may be bonded to form a hydrocarbon ring with the ring carbon atoms ; and n is 1 or 2. The novel oxotitanium complex is particularly useful as an asymmetric reaction catalyst in glyoxylate-ene or aldol reactions, and processes for producing β-hydroxy ketones or a-hydroxy carboxylic acid esters in its presence are also disclosed.
本发明公开了通式 (I) 所代表的新型氧化钛络合物:
其中 R1 和 R2 可以是氢、低级烷基、低级烷氧基、卤素、苯基、取代苯基、三烷基硅基、单烷基二苯基硅基、二烷基单苯基硅基、三苯基硅基、取代三苯基硅基或低级烷氧基羰基;R1 和 R2 可以键合,与环上碳原子形成烃环;R3 和 R4 可以不同,各自代表氢、低级烷基、低级烷氧基、苯甲酰基、苯磺酰基或卤素;R3 和 R4 可以键合,与环上碳原子形成烃环;n 为 1 或 2。这种新型氧化钛络合物在乙醛酸烯或醛醇反应中作为不对称反应催化剂特别有用,还公开了在其存在下生产β-羟基酮或a-羟基羧酸酯的工艺。