Although high enantioselectivity of [2,3]-sigmatropic rearrangement of sulfonium ylides (Doyle-Kirmse reaction) has proven surprisingly elusive using classic chiral Rh(II) and Cu(I) catalysts, in principle it is due to the difficulty in fine discrimination of the heterotopic lone pairs of sulfur and chirality inversion at sulfur of sulfonium ylides. Here, we show that the synergistic merger of new α-diazo pyrazoleamides and a chiral N, N'-dioxide-nickel(II) complex catalyst enables a highly enantioselective Doyle-Kirmse reaction. The pyrazoleamide substituent serves as both an activating and a directing group for the ready formation of a metal-carbene- and Lewis-acid-bonded ylide intermediate in the assistance of a dual-tasking nickel(II) complex. An alternative chiral Lewis-acid-bonded ylide pathway greatly improves the product enantiopurity even for the reaction of a symmetric diallylsulfane. The majority of transformations over a series of aryl- or vinyl-substituted α-diazo pyrazoleamindes and sulfides proceed rapidly (within 5-20 min in most cases) with excellent results (up to 99% yield and 96% ee), providing a breakthrough in enantioselective Doyle-Kirmse reaction.

Vinylcarbene insertion into the nitrogen–hydrogen (N–H) bond of amines allows direct access to α,β-unsaturated γ-amino acid derivatives, meeting a marked challenge in the control of regio- and enantioselectivities. Here, we report a highly γ-selective and enantioselective insertion into N–H bonds of aliphatic or aromatic secondary amines with vinyl substituted α-diazo pyrazoleamides using a high-spin chiral N,N′-dioxide/cobalt­(II) complex catalyst. The method affords a wide variety of valuable optically active Z- and E-type vinyl γ-amino amides. Calculation reveals a spin state change from the quartet cobalt­(II) complex to a doublet Co­(II)-carbene species for facile Z-selective and enantioselective nucleophilic addition.

An N,N′‐dioxide/scandium(III) complex catalyzed, highly efficient conjugate addition of malonic esters to enynes is described. A range of trisubstituted 1,2‐allenyl ketones were obtained in high yields (up to 99 %) with good d.r. (up to 95/5) and excellent ee values (97 %–99 %). Moreover, the products could be easily transformed into chiral furan and 5‐hydroxypyrazoline derivatives, both of which are important skeletons of many biologically active compounds and pharmacologicals.

Catalytic enantioselective [2,3] Stevens and Sommelet-Hauser rearrangements of a-diazo pyrazoleamides with sulfides were achieved by utilizing chiral N,N'-dioxide/nickel-( II )c omplex catalysts.T hese rearrangements proceeded well under mild reaction conditions,p roviding rapid and facile access to aseries of functionalized1,6-dicarbonyls or sulfanesubstituted phenylacetates with high to excellent enantioselectivities.T he catalytic system shows excellent stereocontrol, discriminating between the heterotopic lone pairs of sulfur and controlling both the 1,3-proton transfer and the [2,3]-s rearrangement.Scheme 1. Sulfur-containing drugs and catalytic asymmetric [2,3] sigmatropic rearrangements.

An enantioselective electrophilic α-cyanation of 1-indanone-derived β-keto esters and β-keto amides using a hypervalent iodine as the cyanide-transfer reagent was realized. A chiral N,N'-dioxide was used as the efficient bifunctional organocatalyst in the presence of inorganic base, which gave the corresponding α-cyano dicarbonyl compounds in yields of 50-99% with good enantioselectivities (87-97% ee).