Yong-Chua Teo

Enantioselective allylation of ketones catalyzed by chiral In(III)-PYBOX complexes

In the presence of 20 mol% of chiral catalytic complex prepared from In(OTf)3 and chiral PYBOX, allyltributylstannane reacted with achiral ketones to afford the corresponding homoallylic alcohols in moderate to high enantioselectivities (54-95% ee), which constitutes the first example of enantioselective allylation of ketones catalyzed by the chiral In(III)-PYBOX complex.

Indium-catalyzed C(sp3)–H functionalization of 2-methylazaarenes through direct benzylic addition to trifluoromethyl ketones

The application of trivalent indium for the Lewis acid-catalyzed C(sp3)–H functionalization of 2-methylazaarenes is reported. InCl3 was discovered to catalyze the direct addition of the benzylic C–H bond in the azaarenes to trifluoromethyl ketones. An ample number of substrates were cogently demonstrated to give the products as trifluoromethylated alcohols whereby in some cases, up to quantitative yield (99%) could be obtained.

Catalytic asymmetric allylation of aldehydes via a chiral indium(III) complex

A chiral indium complex has been discovered to effect high enantioselectivities in the addition of allyltributyl stannanes to aldehydes. The allylation of a variety of aromatic, alpha,beta-unsaturated and aliphatic aldehydes resulted in good yields and high enantioselectivities (90-96% ee).

Regioselective copper-diamine-catalyzed C–H arylation of 1,2,4-triazole ring with aryl bromides

A convenient methodology for the regioselective C–H arylation of 1,2,4-triazole ring was developed. Using a benchtop stable Cu-diamine catalyst system, C–H functionalization of a simple 1,2,4-triazole substrate with various aryl bromides was regioselectively accomplished at the C5 position of the triazole ring.