V-catalyzed Synthesis Of Isoquinolinediones From Acrylamides And HIRs

Isoquinolinediones have received widespread attention due to their unique structural properties and their potentially biological activities.Compared with the well-established late-transition metals,the isoquinolinedione synthesis through early-transition metal catalysis remained largely lagged behind.Vanadium as early-transition metal is the 20th most abundant element in the earth's crust and is inexpensive.Thus,the development of vanadium catalysis on isoquinolinedione synthesis remains a desirable and challenging goal.Based on our previous work,we synthesized the benzene-bridged divanadium complex(?-?⁶:?⁶-C₆H₆)[V(Nacnac)]₂(2A),which can catalyze the reaction between acrylamides and hypervalent iodine(III)reagents(HIRs)to generate a series of isoquinolinediones bearing a quaternary carbon center.This paper has the following work:(1)The synthesis and structure of benzene-bridged divanadium complex(?-?⁶:?⁶-C₆H₆)[V(Nacnac)]₂(2A).(2)Isoquinolinedione synthesis from the reaction between acrylamides and HIRs enabled by benzene-bridged divanadium complex 2A.(3)Preliminary mechanism experiment carried out with 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)revealed that an intermolecular radical alkylation/intramolecular radical cyclization/re-aromatization cascade may occur in the reaction.(4)The synthesis of substrates including various acrylamides and aliphatic acid-derived HIRs.