Multifold Bond Cleavage and Formation between MeOH and Quinoxalines (or Benzothiazoles): Synthesis of Carbaldehyde Dimethyl Acetals

被引：38

作者：

Liu, Yunkui ^{[1
,2
]}

Jiang, Bo ^{[1
]}

Zhang, Wei ^{[1
]}

Xu, Zhenyuan ^{[1
]}

机构：

[1] Zhejiang Univ Technol, State Key Lab Breeding Base Green Chem Synth Tech, Hangzhou 310014, Zhejiang, Peoples R China

[2] Wenzhou Univ, Coll Chem & Mat Engn, Wenzhou 325027, Zhejiang, Peoples R China

来源：

JOURNAL OF ORGANIC CHEMISTRY | 2013年 / 78卷 / 03期

关键词：

CROSS-COUPLING REACTION; ELECTRON-WITHDRAWING SUBSTITUENTS; FREE-RADICAL REACTIONS; C-H ACTIVATION; PALLADIUM(II)-CATALYZED ACETALIZATION; HIGHLY EFFICIENT; ALCOHOLS; METHANOL; OXIDATION; DERIVATIVES;

D O I：

10.1021/jo302450f

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

A K2S2O8-mediated direct cross-coupling of quinoxalines (or benzothiazoles) with methanol leading to 2-quinoxalinyl (or 2-benzothiazolyl) carbaldehyde dimethyl acetals has been achieved. 2-Quinoxalinyl carbaldehyde dimethyl acetals were readily converted into 2-quinoxalinyl carbaldehydes in good to excellent yields under acidic conditions. Preliminary mechanistic studies suggest that the reaction proceeds via multifold bond cleavage and formation between methanol and N-heterocycles involving a dioxygen-participated radical process. This method allows for the synthesis of a variety of 2-quinoxalinyl (or 2-benzothiazolyl) carbaldehyde dimethyl acetals directly via cross-coupling of simple N-heterocyclic C-H bond and methanol under aldehyde-, add-, and transition-metal-free conditions.

引用

页码：966 / 980

页数：15

共 81 条

[1] A warning on the use of radical traps as a test for radical mechanisms:: They react with palladium hydrido complexes [J].