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Highly efficient kinetic resolution of 2 H-azirines by an asymmetric imine amidation was achieved in the presence of a chiral N, N′-dioxide/ScIII complex, thus providing a promising method to obtain the enantioenriched 2 H-azirine derivatives and protecting-group free aziridines at the same time. It is rare to find an example of N1 of an oxindole participating in a reaction over C3. Moreover, chiral 2 H-azirines were stereospecifically transformed into an unprotected aziridine and α-amino ketone. [ABSTRACT FROM AUTHOR]

The asymmetric propargyl Claisen rearrangement provides a convenient entry to chiral allene motifs. Herein, we describe the development of a kinetic resolution and asymmetric rearrangement of racemic propargyl vinyl ethers. This transformation afforded chiral allene products along with the enantiomerically enriched substrate in good yields with excellent diastereo- and enantioselectivity. The complete chirality transfer and facially selective rearrangement enabled the simultaneous construction of an axially chiral allenic unit and a quaternary carbon stereocenter. [ABSTRACT FROM AUTHOR]

Highly efficient catalytic asymmetric Claisen rearrangements of O-propargyl β-ketoesters and O-allyl β-ketoesters have been accomplished under mild reaction conditions. In the presence of the chiral N,N'-dioxide/NiII complex, a wide range of allenyl/allyl-substituted all-carbon quaternary β-ketoesters was obtained in generally good yield (up to 99%) and high diastereoselectivity (up to 99:1 d.r.) with excellent enantioselectivity (up to 99% ee). [ABSTRACT FROM AUTHOR]

A highly efficient N,N′-dioxide-scandium(III) complex catalytic system has been developed for the asymmetric vinylogous Michael reaction of α-angelica lactone and its derivatives to α,β-unsaturated γ-keto esters, affording the corresponding γ,γ-disubstituted butenolide products in moderate to good yields (up to 93%) with high dr (up to >19:1) and ee values (up to 97%) under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Abstract: The asymmetric domino three-component Knoevanagel-Diels–Alder addition (ATCDA) reaction, as an important methodology, has been utilized to construct complex product from ordinary starting materials. In this report, many typical organoamine catalysts were investigated to achieve highly efficient asymmetric three-component reaction of enones 2, aldehydes 3 and Meldrum’s acid 4. Various pharmacological multi-substituted spiro[5,5]undecane-1,5,9-triones promoted by 9-amino-9-deoxy-epi-quinine 1 g in one-pot, were obtained in moderate to good yields (up to 81%) with excellent diastereo-(>99:1 dr) and enantioselectivities (up to 97% ee). Meanwhile, based on the controlled experiments and analytical data, a reasonable mechanism of dual-activity for this reaction has been proposed. [Copyright &y& Elsevier]