Catalytic Henryreactions of aliphatic aldehydes and prochiral nitro compounds were investigated usingcopper(II) complexes of 14 C1‐symmetrical ligands derived from (1R,2R)(−)‐diaminocyclohexane. β‐Nitro alcohols with syn:anti ratios of up to 5.7 and excellent ee values for both diastereosimers were obtained.
使用衍生自(1 R,2 R)(-)-二氨基环己烷的14 C 1对称配体的铜(II)配合物研究了脂肪醛和前手性硝基化合物的催化亨利反应。β硝基醇与顺式:反向上的比率5.7和优异的ee值获得两个diastereosimers值。
Efficient Diastereoselective and Enantioselective Nitroaldol Reactions from Prochiral Starting Materials: Utilization of La-Li-6,6'-Disubstituted BINOL Complexes as Asymmetric Catalysts
Asymmetric nitroaldol reaction catalyzed by copper–diamine complexes: selective construction of two contiguous stereogenic centers
作者:Rafał Kowalczyk、Jacek Skarżewski
DOI:10.1016/j.tetasy.2009.10.001
日期:2009.11
Chiral copper(II) complexes of secondary bisamines derived from 1,2-diaminocyclohexane were successfully used in the diastereoselective nitroaldol reaction. The reactions were carried out in the presence of 10 mol % of the Cu(II) complex and 7.7 mol % of i-Pr2NEt in 2-propanol at -30 degrees C. Good to excellent yields, enantioselectivities of up to 99%, and moderate to excellent diastereoselectivities were obtained for both aromatic or aliphatic aldehydes and various prochiral nitrocompounds forming the corresponding beta-nitroalcohols with two contiguous stereocenters. (C) 2009 Elsevier Ltd. All rights reserved.
CATALYTIC ASYMMETRIC SYNTHESIS OF NITROALDOLS USING A LANTHANUM-LITHIUM-BINOL COMPLEX: (2S,3S)-2-NITRO-5-PHENYL-1,3-PENTANEDIOL
作者:Sasai, Hiroaki、Watanabe, Shizue、Suzuki, Takeyuki、Shibasaki, Masakatsu、Havas, Fabien、Magomedov, Nabi A.、Hart, David J.