Modular assembly of cyclometalated gold(III) complexes by choosing appropriate bidentate C,N-donor ligands and ancillary ligands for chemoselective cysteine modification of peptides and proteins via C-S bond-forming reductive elimination has been achieved.

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Cl 2 ] 1a-l (HC _ N = arylpyridines) and a PEG-linked complex 1m were synthesized. Complexes 1a-m are effective in catalyzing the synthesis of propargylic amines, chiral allenes and isoxazoles. Six-membered ring cyclometallated goldA C H T U N G T R E N N U N G (III) complexes 1f-l exhibited higher catalytic activity than five-membered ring cyclometallated goldA C H T U N G T R E N N U N G (III) complexes 1a-e. The diastereoselectivity of propargylic amines could be tuned by using chiral aldehyde and/ or amine substrates. Excellent enantioselectivities (90-98% ee) were achieved in chiral allene synthesis. Chiral allene racemization could be minimized by using 1f as catalyst. The PEG-linked catalyst 1m is the most catalytically active towards synthesis of propargylic amines, in which case a product turnover of 900 was achieved. Moreover, 1m could be repeatedly used for 12 reaction cycles, leading to an overall turnover number of 872.

An efficient gold-catalyzed amide synthesis from aldehydes and amines in aqueous medium under mild reaction conditions has been developed.

Stable bis-cyclometallated gold(III) complexes were developed as efficient catalysts for organic transformation reactions by using two strategies: (1) construction of distorted square planar gold(III) complexes and (2) dual catalysis by gold(III) complexes and silver salts.