Enantioselective Cyanosilylation of Alkynyl Ketones Catalyzed by Combined Systems Consisting of Chiral Ruthenium(II) Complex and Lithium Phenoxide
Enantioselective Cyanosilylation of Alkynyl Ketones Catalyzed by Combined Systems Consisting of Chiral Ruthenium(II) Complex and Lithium Phenoxide
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DOI：
10.1002/adsc.201701593
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发表时间：
2018-04
影响因子：
5.4
通讯作者：
T. Ohkuma;Nobuhito Kurono;Y. Sakaguchi;Kohei Yamauchi;Taiga Yurino
中科院分区：
文献类型：
--
作者：
T. Ohkuma;Nobuhito Kurono;Y. Sakaguchi;Kohei Yamauchi;Taiga Yurino
以氨基酸/2，2 ′-双（二苯基膦基）-1，1 ′-联萘（BINAP）/钌（II）配合物和苯酚锂（Ru/Li cat.）为催化剂体系，研究了炔基酮的不对称硅腈化反应。研究了该反应在-78 °C下用叔丁基甲基醚（TBME）进行，底物与催化剂的摩尔比（S/C）高达2000。一系列简单的和官能化的酮被转化为炔基叔氰醇衍生物，高达99%ee。根据底物结构适当选择催化剂的氨基酸配体对于实现高对映选择性和宽底物范围至关重要。还检查了手性氰醇产物向官能化内酯的转化。
Asymmetric cyanosilylation of alkynyl ketones with the catalyst systems consisting of amino acid/2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl (BINAP)/ruthenium(II) complex and lithium phenoxide (Ru⋅Li cat.) was studied. The reaction was conducted intert‐butyl methyl ether (TBME) at −78 °C with a substrate‐to‐catalyst molar ratio (S/C) as high as 2000. A series of simple and functionalized ketones was converted into the alkynyl tertiary cyanohydrin derivatives in up to 99% ee. Appropriate selection of an amino‐acid ligand of the catalyst according to the substrate structure was crucially important to achieve high enantioselectivity and a wide scope of substrates. Transformation of the chiral cyanohydrin product into a functionalized lactone was also examined.