Synthesis 2007(7): 989-998  
DOI: 10.1055/s-2007-965983
PAPER
© Georg Thieme Verlag Stuttgart · New York

[1,1′-Bis(diphenylphosphino)ferrocene]dichloropalladium/1,1′-Bis(diphenylphosphino)ferrocene Catalyzed Synthesis of 2,3-Diamino-1,4-naphthoquinones

Xiao Lei Wanga, Xiu Fang Zhenga, Lei Wanga, John Reiner*a, Wei Lin Xieb, Jun Biao Chang*a,b
a School of Pharmaceutical Science and Technology, Tianjin University, 300072 Tianjin, P. R. of China
Fax: +86(22)27890968; e-Mail: jreiner@tju.edu.cn;
b School of Pharmaceuticals, Xinxiang Medical College, 453003 Xinxiang, P. R. of China
Further Information

Publication History

Received 5 December 2006
Publication Date:
12 March 2007 (online)

Abstract

A general method for the synthesis of 2,3-diamino-1,4-naphthoquinone derivatives via the palladium-catalyzed coupling of 2-amino-3-chloro-1,4-naphthoquinones with amines is described­. The scope and limitations of the coupling process using­ [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium [PdCl2(dppf)], combined with 1,1′-bis(diphenylphosphino)ferrocene (dppf) as a ligand and sodium tert-butoxide as base were investigated, and found to catalyze efficiently the coupling of 2-(arylamino)-3-chloro-1,4-naphthoquinones with primary aryl- and alkylamines. A series of novel 2,3-diamino-1,4-naphthoquinone derivatives previously unavailable were obtained by application of this procedure.