enolates with N-acyl-α-iminophosphonates leading to optically active α-amino phophonates. A copper (II)−diamine complex was shown to be effective in this reaction, and high levels of yield and selectivity were achieved. It is noteworthy that this reaction opens a way to various biologically important, optically active α-aminophosphonate derivatives.
Asymmetric carbonyl addition reactions to benzyloxyaldehydes by binaphthol-titanium catalyst: Anti- vs. Syn-diastereofacial preference in anomalous nonchelation complexation
作者:Koichi Mikami、Satoru Matsukawa、Eiji Sawa、Akinori Harada、Nobuaki Koga
DOI:10.1016/s0040-4039(97)00231-1
日期:1997.3
An anomalous nonchelation diastereofacial selectivity is observed in the titanium-catalyzed carbonyl addition reaction to benzyl-protected alkoxyaldehydes. There is a dichotomy in the sense of syn- vs. anti-diastereofacial preference, dictated by the bulkiness of the migratory group: The sterically demanding silyl group gives syn-diastereofacial preference and the less sterically demanding proton lends to anti-diastereofacial preference. (C) 1997 Elsevier Science Ltd.
Enantioselective Lewis Acid Catalyzed Michael Reactions of Alkylidene Malonates. Catalysis by <i>C</i><sub>2</sub>-Symmetric Bis(oxazoline) Copper(II) Complexes in the Synthesis of Chiral, Differentiated Glutarate Esters
作者:David A. Evans、Tomislav Rovis、Marisa C. Kozlowski、C. Wade Downey、Jason S. Tedrow
DOI:10.1021/ja002246+
日期:2000.9.1
C2-symmetricbis(oxazoline)−Cu(II) complexes 1 catalyze the Mukaiyama Michael reaction of alkylidene malonates and enolsilanes. The use of hexafluoro-2-propanol is essential to induce catalyst turnover. High enantioselectivities are exhibited by bulky alkylidene malonate β-substituents using catalyst 1a. The glutarate ester products are readily decarboxylated to provide chiral 1,5-dicarbonyl synthons