Phenoxytriamine complexes of yttrium: synthesis, structure and use in the polymerization of lactide and epsilon-caprolactone.

Reaction of the phenoxytriamine proligands 2,4-dimethyl-6-bis(2-(diethylamino)ethyl)aminomethlyphenol (HL1) and 2,4-di-tert-butyl-6-bis(2-(diethylamino)ethyl)aminomethylphenol (HL2) with Y[N(SiMe2H)2]3(THF)2 in pentane gave the momomeric complexes L1Y[N(SiMe2H)2]2 (1) and L2Y[N(SiMe2H)2]2 (2). X-Ray structural analysis of 2 shows a 5-coordinate yttrium center. The complexes 1 and 2 catalyze the ring opening polymerization of d-l-lactide and epsilon-caprolactone leading to narrow product polydispersities under mild conditions.

Efficient predetermination of chirality-at-zirconium.

Only one of eight possible diastereomers of the organometallic chiral-at-metal complex [ZrL2(CH2Ph)2] (L = a bidentate, chiral non-racemic pyrdine alcoholate) is observed by NMR spectroscopy in the slow exchange regime.

Enantioselective aziridination using copper complexes of biaryl Schiff bases.

Racemic 2,2'-diamino-6,6'-dimethylbiphenyl is resolved using simulated moving bed chromatography, and the absolute configuration of the enantiomers is confirmed via the X-ray crystal structure of a derivative. The diamine is condensed with a range of aldehydes to give bidentate aldimine proligands L. Molecular structures of the complexes formed between L and Cu(I) fall into two classes; bimetallic double helices ([Cu(2)L(2)](2+)) and monometallic ([CuL](+)).