Enantioselective synthesis of boron-substituted quaternary carbons by NHC-Cu-catalyzed boronate conjugate additions to unsaturated carboxylic esters, ketones, or thioesters.
Enantioselective synthesis of boron-substituted quaternary carbons by NHC-Cu-catalyzed boronate conjugate additions to unsaturated carboxylic esters, ketones, or thioesters.
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DOI：
10.1021/ja104777u
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发表时间：
2010-08-11
影响因子：
15
通讯作者：
Hoveyda, Amir H.
中科院分区：
文献类型：
--
作者：
O'Brien, Jeannette M.;Lee, Kang-sang;Hoveyda, Amir H.
本发明公开了一种有效的Cu催化的方法，用于对无环α，β-不饱和羧酸酯、酮和硫酯的三取代烯烃进行对映选择性硼酸酯共轭加成。所有的转化促进5摩尔%的手性单齿NHC-Cu络合物，衍生自一个容易获得的C1-对称咪唑啉盐，并在市售的双（频哪醇）二硼的存在下。反应是有效的（通常，纯化后产率为60%至>98%）并且以高达>98：2的对映异构体比率（er）递送所需的β-硼基羰基化合物。不饱和硫酯的反应以更高的对映体选择性（相对于羧酸酯或酮）进行，并且所得产物可以通过提供衍生的羧酸酯或各种酮的Ag介导或Pd催化的反应官能化。常规氧化得到β-羟基酮或羧酸酯，酮羟醛产物，其不能通过替代的催化对映选择性方案有效地制备。
An efficient Cu-catalyzed method for enantioselective boronate conjugate additions to trisubstituted alkenes of acyclic α,β-unsaturated carboxylic esters, ketones and thioesters is disclosed. All transformations are promoted by 5 mol % of a chiral monodentate NHC–Cu complex, derived from a readily available C1-symmetric imidazolinium salt, and in the presence of commercially available bis(pinacolato)diboron. Reactions are efficient (typically, 60% to >98% yield after purification) and deliver the desired β-boryl carbonyls in up to >98:2 enantiomer ratio (er). Reactions of unsaturated thioesters proceed with higher enantioselectivity (vs carboxylic esters or ketones), and the resulting products can be functionalized by Ag-mediated or Pd-catalyzed reactions that furnish the derived carboxylic ester or various ketones. Routine oxidation affords β-hydroxy ketones or carboxylic esters, ketone aldol products that cannot be otherwise prepared efficiently by an alternative catalytic enantioselective protocol.
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影响因子：
15
作者：
Lee, Kang-Sang;Brown, M. Kevin;Hoveyda, Amir H.
通讯作者：
Hoveyda, Amir H.
影响因子：
4.9
作者：
Mauleón, P;Carretero, JC
通讯作者：
Carretero, JC
影响因子：
15
作者：
Mazery, RD;Pullez, M;Feringa, BL
通讯作者：
Feringa, BL
影响因子：
16.6
作者：
Brown, M. Kevin;May, Tricia L.;Hoveyda, Amir H.
通讯作者：
Hoveyda, Amir H.
影响因子：
64.8
作者：
Stymiest, Jake L.;Bagutski, Viktor;Aggarwal, Varinder K.
通讯作者：
Aggarwal, Varinder K.