Chiral Proton Catalysis: A Catalytic Enantioselective Direct Aza-Henry Reaction
作者:Benjamin M. Nugent、Ryan A. Yoder、Jeffrey N. Johnston
DOI:10.1021/ja031906i
日期:2004.3.1
during an enantioselectivereaction, this work represents the first example of this phenomenon outside of a protein. A chiral, nonracemic BisAMidine (BAM) ligand was designed, synthesized, and complexed to the proton of a Brønsted acid. The resulting coordination compound catalyzed the production of enantioenriched product from the combination of a Schiff base and nitroalkane (the aza-Henryreaction). This
Versatile Supramolecular Copper(II) Complexes for Henry and Aza-Henry Reactions
作者:Guoqi Zhang、Eiji Yashima、Wolf-D. Woggon
DOI:10.1002/adsc.200900069
日期:2009.6
Abstractmagnified imageChiral supramolecular metal‐organic frameworks assembled from copper complexes catalyse Henry and aza‐Henry reactions of aromatic and aliphatic aldehydes and N‐protected aromatic imines in high yield and good to excellent enantioselectivity. Reactions can be performed in the absence of base in ethanol or water.
Reversal of enantioselectivity using tethered bisguanidine catalysts in the aza-Henry reaction
作者:Helena M. Lovick、Forrest E. Michael
DOI:10.1016/j.tetlet.2008.12.058
日期:2009.3
A series of chiral guanidines were synthesized and shown to efficiently catalyze the aza-Henry reaction. Modifications of the catalyst Structure revealed important selectivity trends as well as an intriguing reversal in stereoselectivity with bisguanidine variants. These compounds were applied to the aza-Henry reaction between N-Boc imines and nitroalkanes generating the beta-nitroamines in up to 77% ee and up to 20:1 diastereoselectivity. (C) 2009 Elsevier Ltd. All rights reserved.