Indium-mediated asymmetric intramolecular allenylation of N-tert-butanesulfinyl imines: efficient and practical access to chiral 3-allenyl-4-aminochromanes.

An efficient method for the preparation of highly optically active 3-allenyl- and 3-vinyl-4-aminochromanes by In-mediated intramolecular cyclization has been developed. The synthetic utilities of the approach were demonstrated by the construction of various chiral polycyclic heterocycles, especially the interesting spiroheterocyclic compound 9 and steroid analogue 10.

Rhodium-catalyzed enantioselective addition to unsymmetrical α-diketones: tandem one-pot synthesis of optically active 3-tetrasubstituted isochroman derivatives.

The domino effect: An efficient and general catalytic one-pot synthesis of quaternary-substituted isochroman derivatives has been developed (see scheme). The cascade transformation relies on rhodium-catalyzed highly regio- and enantioselective 1,2-addition of arylboronic acids to unsymmetrical α-diketones and intramolecular etherification or esterification, and provides a variety of enantioenriched isochromanones under exceptionally mild conditions.

Rhodium-catalyzed enantioselective 1,2-addition of arylboronic acids to heteroaryl α-ketoesters for synthesis of heteroaromatic α-hydroxy esters.

The first example of catalytic asymmetric 1,2-addition of arylboronic acids to heteroaryl α-ketoesters has been developed for the highly efficient and enantioselective synthesis of quaternary carbon-containing heteroaromatic α-hydroxy esters. The reaction works well with a variety of α-ketoesters including 3-indoleglyoxylates, 3-benzofuranglyoxylates and 3-benzothiopheneglyoxylates under very mild conditions, affording the corresponding products in moderate to good yields with high enantiomeric excesses (up to 97%).

Efficient synthesis of optically active α-quaternary amino acids by highly diastereoselective [2,3]-rearrangement of allylic ammonium ylides.

A pincer-like chiral auxiliary strategy for synthesizing various optically active α,α-disubstituted amino acids in high yields with excellent enantioselectivities is described.

Design of N-cinnamyl sulfinamides as new sulfur-containing olefin ligands for asymmetric catalysis: achieving structural simplicity with a categorical linear framework.

The design and development of an extraordinarily interesting new class of chiral sulfur-olefin hybrid ligands with remarkable structural simplicity were described. These unique sulfinamide-olefin ligands have been proved to be highly effective ligands in rhodium-catalyzed asymmetric 1,4-addition reactions of aryl boronic acids to α,β-unsaturated carbonyl compounds (up to 99% yield and 98% ee).

Design of chiral sulfoxide-olefins as a new class of sulfur-based olefin ligands for asymmetric catalysis.

The design and development of a novel class of chiral sulfur-olefin hybrid ligands with high synthetic feasibility are described. These new sulfoxide-olefin ligands showed excellent catalytic activities and enantioselectivities (up to 98% ee) in rhodium-catalyzed asymmetric 1,4-addition reactions of aryl boronic acids to α,β-unsaturated carbonyl compounds.