An unusual electronic effect of an aromatic-F in phase-transfer catalysts derived from Cinchona-alkaloid

被引：145

作者：

Jew, SS ^{[1
]}

Yoo, MS

Jeong, BS

Park, IY

Park, HG

机构：

[1] Seoul Natl Univ, Coll Pharm, Seoul 151742, South Korea

[2] Chungbuk Natl Univ, Coll Pharm, Cheongju 361763, South Korea

来源：

ORGANIC LETTERS | 2002年 / 4卷 / 24期

关键词：

D O I：

10.1021/ol0267679

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

[GRAPHICS] Various N-benzylcinchonidinium salts were prepared to study electronic factors in the catalytic enantioselective phase-transfer alkylation of glycine anion equivalent. An ortho-fluoro substituent on the benzyl group in the quaternary ammonium salt dramatically increased the enantioselectivity In the alkylation. 0(9)-Allyi-N-2',3',4'-trifluorobenzylhydrocinchonidinium bromide (27), which gave the highest enantioselectivity of the catalysts studied, was used to prepare 12 alpha-alkylated amino acid derivatives in 94similar to>99% ee.

引用

页码：4245 / 4248

页数：4

共 25 条

[21]

Park HG, 2002, ANGEW CHEM INT EDIT, V41, P3036, DOI 10.1002/1521-3773(20020816)41:16<3036::AID-ANIE3036>3.0.CO

[22]

2-3

[23] Trimeric Cinchona alkaloid phase-transfer catalyst:: α,α′,α"-tris[O(9)-allylcinchonidinium]mesitylene tribromide [J].