We report the diastereoselective addition of a wide range of nucleophiles to chiral pyrazolines to provide facile access to a range of useful densely functionalized building blocks for asymmetric synthesis. Coupled with the asymmetric cycloaddition reaction of Me(3)SiCHN(2) to chiral acrylates, access to these chiral heterocycles is considerably expanded.

[formula: see text] In the presence of catalytic quantites of Cu(OTf)2 the novel hydroxamic acid anhydride salt functions competently in the trifluoroacetamidation of sulfides to afford N-(trifluoroacetyl)sulfilimines. The salient features of this salt include its ease of synthesis from the inexpensive, commercially available starting materials trifluoroacetic anhydride and hydroxylamine hydrochloride.