Addition-Cyclization Protocol for the Enantioselective Synthesis of Furans

Abstract

Significance: The tandem addition-cyclization reaction described in this report represents a highly efficient approach towards 1,3-dihydrobenzofurans and tetrasubstituted furans. The reaction is carried out in a one-pot manner and provides products with good yields and high selectivities. Interestingly, extremely high Z-diastereoselectivity is observed, most likely arising from the subsequent regioselective 5-exo-dig cyclization reaction. Comment:The authors have shown that the reaction proceeds well for a series of aromatic and aliphatic aldehyde substrates. Moreover, different organozinc reagents can be efficiently used for the reaction, which renders this transformation more general. Hopefully, this method can be expanded to other classes of carbonyl-like substrates and the selectivitiy improved.