Iron(II) Phthalocyanine-Catalyzed Homodimerization and Tandem Diamination of Diazo Compounds with Primary Amines: Access to Construct Substituted 2,3-Diaminosuccinonitriles in One-Pot

• Published in: Journal of organic chemistry 2024-06, Vol.89 (11), p.7718-7726
• Main Authors: Wang, Gang, Yuan, Jia-Li, Zhou, Rong, Zou, Huai-Bo
• Format: Article
• Language: English
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/acs.joc.4c00376

We herein first report the homodimerization and tandem diamination of diazo compounds with primary amines catalyzed by the iron­(II) phthalocyanine (PcFe­(II)), which can construct one C–C bond and two C–N bonds within 20 min in one-pot. Compared to the traditional metal-catalyzed N–H insertion reaction between amines with diazo reagents, the developed reaction almost does not generate the N–H insertion product, but the homodimerization/tandem diamination product. The proposed mechanism studies indicate that primary amines play a crucial role in the homocoupling of diazo compounds via dimerization of iron­(III)–acetonitrile radical generated from the reaction between diazoacetonitrile with PcFe­(II) coordinated by bis­(amines); the β-hydride elimination is involved, and then, the attack of primary amines toward the carbon atoms on the formed C–C bond is followed. Moreover, this novel reaction can be used to effectively prepare substituted 2,3-diaminosuccinonitriles with high yields and even up to >99:1 d.r., encouragingly these products contain both 1,2-diamines and succinonitrile motifs, which are two classes of important organic compounds with significant applications in many yields. This reaction is also suitable for the gram-scale preparation of 2,3-bis­(phenylamino)­succinonitrile (2a) with a yield of 84%. Therefore, the developed reaction represents a new type of transformation.