Novel approach to multifunctionalized homoallylic alcohols via regioselective ring opening of aryl oxiranes with 3-iodo allenoates

[reaction: see text] 3-Iodo allenoates were generated in situ and utilized, for the first time, in the ring opening of oxiranes in a regioselective fashion. This simple one-pot three-component reaction protocol provides easy access to highly functionalized homoallylic alcohols in good yields and moderate to very good (Z/E) selectivity. The two functional groups (ester and halogen) can be further subjected to many synthetic transformations.     

Chiral N-phosphonyl imine chemistry: new reagents and their applications for asymmetric reactions

Novel chiral N-phosphonyl imines 2 have been designed and synthesized using chiral N-phosphoramide 1. These N-phosphonyl imines have been successfully utilized for asymmetric aza-Darzens reaction and asymmetric aza-Henry reaction. The C₂-symmetric chiral auxiliary tolerates oxidation, is not sensitive to racemization and can be recycled for large scale synthesis.     

Chiral N-phosphonyl imine chemistry: asymmetric 1,2-additions of allylmagnesium bromides

Chiral N-phosphonyl homoallylic amines were synthesized by the reaction of allylmagnesium bromide with chiral N-phosphonyl imines. The C₂-symmetric chiral N-phosphonyl group was optimized for this reaction. Excellent yields and good diastereoselectivities were obtained for eight examples.