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09 Apr 02:50

The Synthesis of Benzimidazoles and Quinoxalines from Aromatic Diamines and Alcohols by Iridium-Catalyzed Acceptorless Dehydrogenative Alkylation

by Toni Hille, Torsten Irrgang, Rhett Kempe
Feixiang0312

本科课题

Abstract

Benzimidazoles and quinoxalines are important N-heteroaromatics with many applications in pharmaceutical and chemical industry. Here, the synthesis of both classes of compounds starting from aromatic diamines and alcohols (benzimidazoles) or diols (quinoxalines) is reported. The reactions proceed through acceptorless dehydrogenative condensation steps. Water and two equivalents of hydrogen are liberated in the course of the reactions. An Ir complex stabilized by the tridentate P^N^P ligand N2,N6-bis(di-isopropylphosphino)pyridine-2,6-diamine revealed the highest catalytic activity for both reactions.

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Aromatic diamines were reacted with alcohols and diols to form benzimidazoles or quinoxalines, respectively (see scheme). In the course of the reactions, water and two equivalents of hydrogen gas were eliminated/liberated. An Ir complex stabilized by a tridentate P N P ligand was found to be an efficient catalyst in these reactions.

25 Mar 02:12

Catalytic Mechanisms of Direct Pyrrole Synthesis via Dehydrogenative Coupling Mediated by PNP-Ir or PNN-Ru Pincer Complexes: Crucial Role of Proton-Transfer Shuttles in the PNP-Ir System

by Shuanglin Qu, Yanfeng Dang, Chunyu Song, Mingwei Wen, Kuo-Wei Huang and Zhi-Xiang Wang
Feixiang0312

厉害

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Journal of the American Chemical Society
DOI: 10.1021/ja411568a
25 Mar 02:12

Homogeneous Perdehydrogenation and Perhydrogenation of Fused Bicyclic N-Heterocycles Catalyzed by Iridium Complexes Bearing a Functional Bipyridonate Ligand

by Ken-ichi Fujita, Yui Tanaka, Masato Kobayashi and Ryohei Yamaguchi
Feixiang0312

又来了一篇

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Journal of the American Chemical Society
DOI: 10.1021/ja5001888
19 Mar 13:31

Reductive Amination without an External Hydrogen Source

by Denis Chusov, Benjamin List

Abstract

A method of reductive amination without an external hydrogen source is reported. Carbon monoxide is used as the reductant. The reaction proceeds efficiently for a variety of carbonyl compounds and amines at low catalyst loadings and is mechanistically interesting as it does not seem to involve molecular hydrogen.

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Look, no H2! Reductive amination without an external hydrogen source has been developed using carbon monoxide as the reductant and rhodium acetate (0.2–1 mol %) as catalyst. The method tolerates a variety of functional groups and provides target amines in good to excellent yields.

27 Dec 08:57

Asymmetric Cross-Dehydrogenative Coupling Enabled by the Design and Application of Chiral Triazole-Containing Phosphoric Acids

by Andrew J. Neel, Jörg P. Hehn, Pascal F. Tripet and F. Dean Toste
Feixiang0312

毕业论文添加

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Journal of the American Chemical Society
DOI: 10.1021/ja407410b
21 Nov 02:22

CuI-Catalyzed C1-Alkynylation of Tetrahydroisoquinolines (THIQs) by A3 Reaction with Tunable Iminium Ions

by Qin-Heng Zheng, Wei Meng, Guo-Jie Jiang and Zhi-Xiang Yu
Feixiang0312

……郁闷啊

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Organic Letters
DOI: 10.1021/ol402517e