Catalytic hydrogenation of unactivated amides enabled by hydrogenation of catalyst precursor
摘要:
A general method for catalytic hydrogenation of unactivated amides was achieved. During the catalyst induction period, a novel structural change was observed involving full hydrogenation of the interior unsaturated bonds of the pyridines of the Ru-containing catalyst precursor. Based on this observation, the mechanism of amide hydrogenation may involve a two-step pathway, wherein the Ru catalyst having an H-Ru-N-H functionality is generated in the first step, followed by the amide carbonyl group interacting with the outer, rather than the inner, sphere of the Ru catalyst. (c) 2013 Elsevier Ltd. All rights reserved.
Ligand, metal complex containing ligand, and reaction using metal complex containing ligand
申请人:National University Corporation Nagoya University
公开号:US09463451B2
公开(公告)日:2016-10-11
A hydrogen transfer reaction may be more efficiently promoted by using a metal complex represented by Formula (2):
(wherein, R1 to R8 are the same or different, and each represents a hydrogen atom, a substituted or unsubstituted alkyl group or the like; or wherein; R1 and R2, R2 and R3, R3 and R4, R4 and R5, and R5 and R6 are respectively bonded to each other to form a bivalent hydrocarbon group;
R9 are the same or different, and each represents an alkyl group or cycloalkyl group;
M is ruthenium (Ru) or the like;
X is a ligand; and
n is 0, 1 or 2).
More specifically, the metal complex enables a hydrogenation reaction of various substrates having a stable carbonyl group or the like to be advanced with a high yield under mild conditions.
benzylamine, N-benzylformamide was obtained in 77% yield. 1-Octene was hydroamidated with benzylamine to N-benzylnonanamide in 67% yield (the selectivity to its linear isomer was 81%). These reactions appear to include ruthenium carbamoyl complex as the common key intermediate.
十二碳三钌(Ru 3(CO)12)是一种有效的均相催化剂前体,用于在一氧化碳压力为40 kg cm -2的条件下在120–180°C下进行胺的羰基化和烯烃的加氢酰胺化。通过苄胺的羰基化,以77%的产率获得了N-苄基甲酰胺。用苄胺将1-辛烯加氢酰胺化为N-苄基壬酰胺,产率为67%(其线性异构体的选择性为81%)。这些反应似乎包括钌氨基甲酰基络合物作为常见的关键中间体。
Rh(I)-Catalyzed Hydroamidation of Olefins via Selective Activation of N–H Bonds in Aliphatic Amines
Hydroamidation of olefins constitutes an ideal, atom-efficient method to prepare carboxylic amides from easily available olefins, CO, and amines. So far, aliphatic amines are not suitable for these transformations. Here, we present a ligand- and additive-free Rh(I) catalyst as solution to this problem. Various amides are obtained in good yields and excellent regioselectivities. Notably, chemoselective
compounds and good nucleophiles as substrates. Herein, we developed a copper‐catalyzedcarbonylative transformation of cycloalkanes and amides. Imides were prepared in good yields by carbonylation of a C(sp3)−H bond of the cycloalkane with the amides acting as weak nucleophiles. Notably, this is the first report of copper‐catalyzedcarbonylative C−H activation.