本文公开了以硫酸铁( III )为再氧化剂的活性末端烯烃的高效钯催化抗马尔科夫尼科夫氧化缩醛化反应。该方法需要温和的反应条件,并显示出对抗马尔科夫尼科夫产物的高区域选择性以及与多种官能团的相容性。硫酸铁( III ) 是该方法中使用的唯一再氧化剂。各种烯烃,如乙烯基芳烃、芳基烯丙基醚、丙烯酸芳基或苄基丙烯酸酯和高烯丙醇都反应良好,提供抗马尔科夫尼科夫缩醛,其中一些代表正交官能化的 1,3-和 1,4-二氧化化合物。
Insertion of unsaturated systems such as alkynes and olefins into unactivated sp3 CH bonds remains an unexplored problem. We herein address this issue by successfully incorporating a wide variety of functionalized alkynes and electron‐deficient olefins into the unactivated sp3 CH bond of pivalic acid derivatives with excellent syn‐ and linear‐ selectivity. A strongly chelating 8‐aminoquinoline directing
Development and Analysis of a Pd(0)-Catalyzed Enantioselective 1,1-Diarylation of Acrylates Enabled by Chiral Anion Phase Transfer
作者:Eiji Yamamoto、Margaret J. Hilton、Manuel Orlandi、Vaneet Saini、F. Dean Toste、Matthew S. Sigman
DOI:10.1021/jacs.6b11367
日期:2016.12.14
Enantioselective 1,1-diarylation of terminal alkenes enabled by the combination of Pd catalysis with a chiralanionphasetransfer (CAPT) strategy is reported herein. The reaction of substituted benzyl acrylates with aryldiazonium salts and arylboronic acids gave the corresponding 3,3-diarylpropanoates in moderate to good yields with high enantioselectivies (up to 98:2 er). Substituents on the benzyl
Mechanistic Investigations of the Pd(0)-Catalyzed Enantioselective 1,1-Diarylation of Benzyl Acrylates
作者:Manuel Orlandi、Margaret J. Hilton、Eiji Yamamoto、F. Dean Toste、Matthew S. Sigman
DOI:10.1021/jacs.7b06917
日期:2017.9.13
A mechanistic study of the Pd-catalyzed enantioselective 1,1-diarylation of benzyl acrylates that is facilitated by a chiral anion phase transfer (CAPT) process is presented. Kinetic analysis, labeling, competition, and nonlinear effect experiments confirm the hypothesized general mechanism and reveal the role of the phosphate counterion in the CAPT catalysis. The phosphate was found to be involved
Conjugate addition is among the most important synthetic protocols for constructing carbon skeletons and is widely used to synthesize natural products and drugs. However, asymmetric catalysis studies have mainly focused on constructing stereogenic centers arising from conjugate alkenes. Here, we report the first photoinduced cobalt-catalyzed dynamic kinetic reductive conjugate addition reaction that
particularly in the absence of directing templates. Activation of a methylene C–H bond in the presence of methyl C–H is underexplored. Here we show activation of a methylene C–H bond in the presence of methyl C–H bonds to form unsaturated bicyclic lactones. The protocol allows the reversal of the general selectivity in aliphatic C–H bond activation. Computational studies suggest that reversible C–H activation