4-Aminothiourea Prolinol<i>tert</i>-Butyldiphenylsilyl Ether: A Chiral Secondary Amine-Thiourea as Organocatalyst for Enantioselective<i>anti</i>-Mannich Reactions
anti-Selective Mannich reactions of N-p-methoxyphenyl (PMP)-protected α-iminoglyoxylate with unmodified aldehydes or ketones were effectively catalyzed by 4-aminothiourea prolinol tert-butyldiphenylsilyl ether. The reactions led to chiral β-amino carbonyl compounds in high yields (up to 94%), excellent diastereo- and enantioselectivities (up to 98% de and >99% ee). The study demonstrated for the first
抗的-选择性曼尼希反应ñ - p -甲氧基苯基(PMP)与未改性的醛或酮-保护的α-iminoglyoxylate得到有效利用4-氨基硫脲脯氨醇催化叔-butyldiphenylsilyl醚。反应导致高收率(高达94%),出色的非对映异构和对映选择性(高达98%de和> 99%ee)的手性β-氨基羰基化合物。该研究首次证明,仲胺-硫脲手性有机催化剂可促进未修饰醛或酮与α-亚氨基乙醛酸酯的直接曼尼希型反应。
Enantioselective Organocatalytic Mannich Reactions with Autocatalysts and Their Mimics
作者:Xinbo Wang、Yongbo Zhang、Haibo Tan、Yanchao Wang、Peng Han、David Zhigang Wang
DOI:10.1021/jo902500b
日期:2010.4.2
The Mannich reactions previously extensively investigated with organocatalysis of L-proline and other related small molecules were reinvestigated with detailed stercochemical analysis of their autocatalysis pathways, through employment of both the products themselves and their close structural mimics as the catalysts. These organo-autocatalytic processes function as meaningful molecular models toward understanding the origin and maintenance of homochirality under biologically relevant conditions.