Synthesis of chiral ligands containing the N-(S)-α-phenylethyl group and their evaluation as activators in the enantioselective addition of Et2Zn to benzaldehyde
作者:Virginia M. Mastranzo、Ericka Santacruz、Gabriela Huelgas、Evelyn Paz、Martha V. Sosa-Rivadeneyra、Sylvain Bernès、Eusebio Juaristi、Leticia Quintero、Cecilia Anaya de Parrodi
DOI:10.1016/j.tetasy.2006.06.005
日期:2006.7
The synthesis of chiral ligands 4–18 derived from N-[(S)-α-phenylethyl]-trans-β-aminocyclohexanols (S,S,S)-1a and (R,R,S)-2 is described. Addition of diethylzinc to benzaldehyde catalyzed by ligands 4–18 (6 mol %) proceeds in fair to good yield (45–86%), and low to good enantioselectivities (1–76% ee). Highest enantioselectivities were induced by ligands (S,S,S)-4 and (S,S,S,S,R,R)-18 (76% and 68%
手性配体的合成4 - 18衍生自ñ - [(小号)-α-苯乙基] -反式-β-aminocyclohexanols(小号,小号,小号) - 1A和(- [R ,- [R ,小号) - 2进行说明。二乙基锌,以通过配位体催化苯甲醛的加成4 - 18(6摩尔%)进行在一般至良好的产率(45-86%),和低的良好的对映选择性(1-76%ee)的。配体(S,S,S)-4诱导最高对映选择性。和(S,S,S,S,R,R)-18(分别为ee的76%和68%)。在两种情况下,甲醇3的主要对映体的构型均为(R)。