Cu(I)/Pd(II)-Catalyzed Intramolecular Hydroamidation and C-H Dehydrogenative Coupling of ortho-Alkynyl-N-arylbenzamides for Access to Isoindolo[2,1-a]Indol-6-Ones

Abstract

An efficient, atom-economic and one-pot synthesis of isoindolo[2,1-a]indol-6-ones via CuI/Pd(OAc)2-catalyzed intramolecular hydroamidation of alkynyl group, and C-H dehydrogenative coupling of ortho-alkynyl-N-arylbenzamides has been developed. This transformation occurs with the use of oxygen as the oxidant, and water is the only by-product. The reaction shows a high tolerance to a variety of functional groups, and affords isoindolo[2,1-a]indol-6-ones in good to high yields.

Bro̷nsted Acid-Catalyzed [5+1] and [4+1] Annulation of Cyclic Anhydrides with o-Alkynylanilines to Construct Fused-N-Heterocycles

“…Syntheses of isoindolo­[2,1- a ]­quinolones were attempted successfully by the reaction of “A” on the use of Ph 3 PCCNPh, Et 3 N, metal catalyst, or DMA (Scheme a). , Recently, Peng et al developed a Pd 2 (dba) 3 -catalyzed carbonylative [5+1] annulation of halogenated benzanilide with alkyne and carbon monoxide . Syntheses of fused tetracyclic 6 H -isoindolo­[2,1- a ]­indol-6-ones were achieved using PhI­(OAc), , CuI-catalysis in the presence of di- t -butyl peroxide (DTBP), or Cu–Pd catalyzed cascade cyclization of ortho -alkynyl- N -arylbenzamides (Scheme b).…”