Diastereo- and Enantioselective Alkylation of alpha-Imino Esters with Enol Silanes Catalyzed by (R)-Tol-BINAP-CuClO(4).(MeCN)(2).
Diastereo- and Enantioselective Alkylation of alpha-Imino Esters with Enol Silanes Catalyzed by (R)-Tol-BINAP-CuClO(4).(MeCN)(2).
复制标题
(R)-Tol-BINAP-CuClO(4).(MeCN)(2) 催化 α-亚氨基酯与烯醇硅烷的非对映和对映选择性烷基化。
DOI：
10.1021/jo981079h
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
T. Lectka
中科院分区：
文献类型：
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作者：
D. Ferraris;Brandon Young;C. Cox;William J. Drury III;T. Dudding;T. Lectka
The past few years have witnessed a profusion of highly efficient, catalytic, enantioand diastereoselective alkylations of carbonyl compounds.1 At the present time, the alkylation of the imino functional group presents a timely challenge in asymmetric catalysis, and recent work has focused on enol silanes, silyl ketene acetals, and TMSCN as carbon-based nucleophiles.2 We recently reported a means to alkylate R-imino ester 1 in up to 98% ee with enol silanes using chiral catalytic late-transition-metal phosphine complexes based on Ag(I), Cu(I), Ni(II), and Pd(II) (eq 1, R′ ) H).3 The best results were obtained with the easy-toprepare catalyst (R)-Tol-BINAP-CuClO4‚(MeCN)2. In this paper, we extend the utility of our reaction to include diastereoand enantioselective variants that yield precursors for a number of pharmacologically active classes of compounds.4 Regardless of the geometry of the enol silane, in many cases, excellent anti diastereoselectivity as well as enantioselectivity (up to 99% ee) can be obtained in the reaction (eq 1).5 In fact, the precise nature of the chiral phosphines we employ is responsible for the diastereoselectivity, as certain achiral bis(triphenylphosphine)-Cu(I) complexes lead to equal amounts of anti and syn products.
DOI：
10.5860/choice.42-5868
发表时间：
1995
期刊：
--
影响因子：
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作者：
A. Katritzky;O. Meth–Cohn;C. Rees
通讯作者：
A. Katritzky;O. Meth–Cohn;C. Rees