Enantioselective transformations of 5-hydroxymethylfurfural via catalytic asymmetric 1,3-dipolar cycloaddition of azomethine ylides.

A catalytic asymmetric 1,3-dipolar cycloaddition between iminoesters derived from 5-hydroxymethylfurfural (HMF) and different activated alkenes is reported. Excellent levels of diastereo and enantioselectivity were obtained when Fesulphos/CuI complex was used as catalyst. This metodology provides an effective and sustainable access to challenging enantioenriched heterocyclic scaffolds and represents one of the rare examples of catalytic asymmetric transformations using HMF as a starting material.

Catalytic enantioselective intramolecular 1,3-dipolar cycloaddition of azomethine ylides with fluorinated dipolarophiles.

An enantioselective synthesis of polycyclic fluorinated pyrrolidines has been achieved by Cu-catalyzed intramolecular 1,3-dipolar cycloaddition of azomethine ylides with fluorinated dipolarophiles. The method displays a wide scope and afforded the desired cycloadducts in high yields with up to 99% ee. These results demonstrate that fluoroalkyl substituents are excellent activating groups in this transformation.