Asymmetric Friedel-Crafts alkylations of indoles with nitroalkenes catalyzed by Zn(II)-bisoxazoline complexes.

[reaction: see text] A novel asymmetric Friedel-Crafts alkylation of indoles with nitroalkenes catalyzed by Zn(II)-bisoxazoline complexes has been developed. The nitroalkylated indoles are synthesized in excellent yields and high enantioselectivities (up to 90% ee). The effects of ligand structure, metal salt, and solvent on the reaction are discussed. The substrates of the reaction can be aromatic, heteroaromatic, and even aliphatic nitroalkenes. The high reactivity and selectivity of the reaction are presumptively attributed to the activation and asymmetric induction of chiral Lewis acids coordinated by nitroalkene substrates through a 1,3-metal bonding model.

Synthesis of spiro diphosphines and their application in asymmetric hydrogenation of ketones.

Synthesis of chiral diphosphine ligands containing a spiro scaffold was described. The ruthenium complexes of these spiro ligands were found to have extremely high activities (S/C up to 100 000) and enantioselectivities (ee up to 99.5%) in the asymmetric hydrogenation of aromatic, heteroaromatic, and alpha,beta-unsaturated ketones.