title: Gold-catalyzed direct hydrogenative coupling of nitroarenes to synthesize aromatic azo compounds.
abstract: The azo linkage is a prominent chemical motif which has found numerous applications in materials science, pharmaceuticals, and agrochemicals. Described herein is a sustainable heterogeneous-gold-catalyzed synthesis of azo arenes. Available nitroarenes are deoxygenated and linked selectively by the formation of N=N bonds using molecular H2 without any external additives. As a result of a unique and remarkable synergy between the metal and support, a facile surface-mediated condensation of nitroso and hydroxylamine intermediates is enabled, and the desired transformation proceeds in a highly selective manner under mild reaction conditions. The protocol tolerates a large variety of functional groups and offers a general and versatile method for the environmentally friendly synthesis of symmetric or asymmetric aromatic azo compounds.
authors.affiliation: Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Fudan University, Shanghai 200433 (P. R. China).
authors.forename: Xiang
authors.initials: X
authors.lastname: Liu
authors.forename: Hai-Qian
authors.initials: HQ
authors.lastname: Li
authors.forename: Sen
authors.initials: S
authors.lastname: Ye
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Liu
authors.forename: He-Yong
authors.initials: HY
authors.lastname: He
authors.forename: Yong
authors.initials: Y
authors.lastname: Cao
keywords: arenes; azo compounds; gold; reduction; supported catalysts