Asymmetric Allylic Alkylation of β-Ketoesters via C–N Bond Cleavage of N-Allyl-N-methylaniline Derivatives Catalyzed by a Nickel–Diphosphine System,ACS Catalysis

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Asymmetric Allylic Alkylation of β-Ketoesters via C–N Bond Cleavage of N-Allyl-N-methylaniline Derivatives Catalyzed by a Nickel–Diphosphine System
ACS Catalysis ( IF 11.3 ) Pub Date : 2020-04-22 , DOI: 10.1021/acscatal.0c01356
Haruki Nagae ₁ , Jingzhao Xia _{1,

2} , Evgueni Kirillov ₃ , Kosuke Higashida ₁ , Koya Shoji ₁ , Valentin Boiteau ₁ , Wanbin Zhang ₂ , Jean-François Carpentier ₃ , Kazushi Mashima ₁

Affiliation

Nickel complexes bearing chiral diphosphine ligands, such as (S)-Tol-MeO-BIPHEP and (S)-H₈-BINAP, serve as efficient catalysts for asymmetric allylic alkylation (AAA) of β-ketoesters, using allylic amines as allyl sources. The reactions proceed with high catalytic activity and high enantioselectivity. N-Methyl-N-phenyl allylic amines were indispensable to achieve the high catalytic activity, to achieve the high enantioselectivity, and to expand the substrate scope to 5- and 7-membered β-ketoesters, whose nickel-catalyzed AAA with allylic alcohols results in low enantioselectivity. On the basis of the kinetics using a catalyst system made of Ni(cod)₂ and (S)-Tol-MeO-BIPHEP, and DFT calculations for the reaction pathway of the AAA reaction mediated by an isolated olefin-coordinated nickel–DPPF complex 4b, we propose a mechanism where protonation of the nitrogen atom of the coordinating allylic amine by β-ketoester is key to cleaving the C–N bond and delivering a cationic π-allyl nickel(II) intermediate.

中文翻译：

通过的C-N键断裂β酮酯的不对称烯丙基烷基化Ñ -Allyl- Ñ由镍-双膦体系催化甲基苯胺衍生物

带有手性二膦配体的镍配合物，例如（S）-Tol-MeO-BIPHEP和（S）-H ₈ -BINAP，使用烯丙基胺作为烯丙基来源，可作为β-酮酸酯不对称烯丙基烷基化（AAA）的有效催化剂。反应以高催化活性和高对映选择性进行。N-甲基-N-苯基烯丙基胺对于实现高催化活性，实现高对映选择性以及将底物范围扩展至5元和7元β-酮酸酯都是必不可少的，其与烯丙基醇的镍催化AAA合成对映选择性低。根据动力学，使用由Ni（cod）₂和（S）-Tol-MeO-BIPHEP，以及由分离的烯烃配位的镍-DPPF配合物4b介导的AAA反应的反应路径的DFT计算，我们提出了一种机制，其中配位的烯丙基胺的氮原子被β-酮酸酯是裂解C–N键并提供阳离子π-烯丙基镍（II）中间体的关键。

更新日期：2020-04-22

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