Concise synthesis of 2,3-disubstituted quinoline derivatives via ruthenium-catalyzed three-component deaminative coupling reaction of anilines, aldehydes and amines

Abstract

The Ru–H complex (PCy3)2(CO)RuHCl (1) was found to be a highly effective catalyst for the three-component deaminative coupling reaction of anilines with aldehydes and allylamines to form 2,3-disubstituted quinoline products....

Benzoquinone Ligand-Enabled Ruthenium-Catalyzed Deaminative Coupling of 2-Aminoaryl Aldehydes and Ketones with Branched Amines for Regioselective Synthesis of Quinoline Derivatives

“…We previously devised a Ru-catalyzed direct deaminative coupling method, which promotes chemoselective C–N bond cleavage of amines and α-amino acid substrates in forming 2-alkylated ketone products . We subsequently discovered that a benzoquinone ligand-enabled ruthenium catalytic system, formed in situ from the reaction of the cationic Ru–H complex [(C 6 H 6 )(PCy 3 )(CO)RuH] + BF 4 – ( 1 ) with 2,3,4,5-tetrachloro-1,2-benzoquinone ( L1 ), is highly effective for mediating the deaminative coupling reactions of amines to form flavanone and quinazolinone derivatives . We successfully utilized the deaminative coupling protocol for promoting regioselective C–C bond cleavage reaction of enones .…”

“…We successfully utilized the deaminative coupling protocol for promoting regioselective C–C bond cleavage reaction of enones . One of the major limitations for these catalytic methods is that they typically require sterically nondemanding and linear amine substrates, although we have been able to use the branched amines in case of formation of quinozolinone derivatives . In an effort to extend the scope and synthetic utility, we sought to develop suitable deaminative coupling methods for branched amine substrates.…”