A Cu-catalyzed asymmetric alkynylation of cyclic N-sulfonyl ketimines was developed, providing the corresponding chiral α-tertiary amines with up to 98% ee. The method tolerates some variations in cyclic N-sulfonyl ketimine and alkyne scope. These products could be used in several transformations, in particular, the products of 6-membered cyclic N-sulfonyl ketimines could be easily converted to linear chiral α-tertiary amines. This asymmetric alkynylation provides an efficient, gram-scale, low-cost transition-metal catalyzed synthesis of chiral α-tetrasubstituted propargylamines.

A method for the preparation of indolines via palladium-catalyzed aerobic intramolecular allylic CH activation was developed. Oxygen was successfully used as oxidant with catalytic amount of 1,4-benzoquinone. 16 examples were reported, the majority of substrates gave moderate to good yields.Download high-res image (112KB)Download full-size image

A Cu-catalyzed asymmetric alkynylation of cyclic N-sulfonyl ketimines was developed, providing the corresponding chiral α-tertiary amines with up to 98% ee. The method tolerates some variations in cyclic N-sulfonyl ketimine and alkyne scope. These products could be used in several transformations, in particular, the products of 6-membered cyclic N-sulfonyl ketimines could be easily converted to linear chiral α-tertiary amines. This asymmetric alkynylation provides an efficient, gram-scale, low-cost transition-metal catalyzed synthesis of chiral α-tetrasubstituted propargylamines.