ABSTRACT
A series of stable phosphonium salts have been synthesized via a novel four-component reaction of an arene nucleophile, 2-heteroatom substituted aryl aldehyde, and phosphine in presence of an acid. The phosphonium salts thus obtained were utilized for the synthesis of a variety of bis-heteroarenes, providing an efficient alternative method to the classical cross-coupling strategies.
ABSTRACT
A Bu3P-mediated cyclization reaction of 3-cinnamoyl-4-hydroxy-2H-chromen-2-ones though electrophilic addition of acyl chlorides towards the synthesis of highly functionalized furo[3,2-c]coumarins bearing a phosphorus ylide moiety is described. These unprecedented cyclization reaction proceeds under mild reaction conditions within short reaction times (1â min to 1â h), and can be further applied in the synthesis of alkenyl-substituted furo[3,2-c]coumarins by the treatment with carbonyl electrophiles under basic conditions.