Regioselective Synthesis of 2H-Indazoles Using a Mild, One-Pot Condensation-Cadogan Reductive Cyclization

被引：100

作者：

Genung, Nathan E. ^{[1
]}

Wei, Liuqing ^{[1
]}

Aspnes, Gary E. ^{[1
]}

机构：

[1] Pfizer Inc, CVMED Med Chem, Groton, CT 06340 USA

来源：

ORGANIC LETTERS | 2014年 / 16卷 / 11期

关键词：

TERVALENT PHOSPHORUS REAGENTS; TYPE-2; DIABETES-MELLITUS; N BOND FORMATION; NITROSO-COMPOUNDS; TRIETHYL PHOSPHITE; ORGANOPHOSPHORUS COMPOUNDS; 2-SUBSTITUTED INDAZOLES; EFFICIENT SYNTHESIS; 2-ARYL-2H-INDAZOLES; HETEROCYCLIZATION;

D O I：

10.1021/ol5012423

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

An operationally simple and efficient one-pot synthesis of 2H-indazoles from commercially available reagents is reported. Ortho-imino-nitrobenzene substrates, generated via condensation, undergo reductive cyclization promoted by tri-n-butylphosophine to afford substituted 2H-indazoles under mild reaction conditions. A variety of electronically diverse ortho-nitrobenzaldehydes and anilines were examined. To further extend the scope of the transformation, aliphatic amines were also employed to form N2-alkyl indazoles selectively under the optimized reaction conditions.

引用

页码：3114 / 3117

页数：4

共 48 条

[1] PALLADIUM COMPLEX-CATALYZED REDUCTIVE N-HETEROCYCLIZATION OF NITROARENES - NOVEL SYNTHESIS OF INDOLE AND 2H-INDAZOLE DERIVATIVES [J].