[EN] ORGANOCATALYSTS AND METHODS OF USE IN CHEMICAL SYNTHESIS [FR] ORGANOCATALYSEURS ET PROCEDES D'UTILISATION DE CES DERNIERS DANS LA SYNTHESE CHIMIQUE
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。
Catalysis of highly stereoselective Mannich-type reactions of ketones with α-imino esters by a pyrrolidine-sulfonamide. Synthesis of unnatural α-amino acids
作者:Wei Wang、Jian Wang、Hao Li
DOI:10.1016/j.tetlet.2004.08.032
日期:2004.9
The novel pyrrolidine-sulfonamide I has been prepared and used successfully to catalyze Mannich-type reactions between ketones and alpha-imino esters. The process is used to efficiently synthesize functionalized alpha-amino acid derivatives with excellent levels of regio-, diastereo-, and enantio-selectivity. (C) 2004 Elsevier Ltd. All rights reserved.