Aziridine sulfides and disulfides as catalysts for the enantioselective addition of diethylzinc to aldehydes.

Enantioselective Addition of Diethylzinc to Aldehydes Catalyzed by a Titanate Complex with a Chiral Tetradentate Ligand.

The addition of dialkylzincs to aldehydes is one of the most widely studied carbon-carbon bond-forming reactions. Many systems reported to date use amino alcohols as ligands and zinc complexes as catalysts.1 The asymmetric version of this alkylation reaction can also be catalyzed by chiral titanate complexes2-4 (e.g., TADDOLs2 and chiral sulfonamides3). We have recently studied a titanate compl...

Synthesis of novel C2-symmetric chiral bis(oxazoline) ligands and their application in the enantioselective addition of diethylzinc to aldehydes

Novel chiral bis(oxazoline) ligands bearing dibenzo[a,c]cycloheptadiene and a dihydroxy group have been synthesized and their application in the catalytic asymmetric addition of diethylzinc to aldehydes investigated. The enantioselectivities for the aromatic aldehydes are generally high and up to 96% ee was obtained. 2003 Elsevier Ltd. All rights reserved.

The synthesis of new oxazoline-containing bifunctional catalysts and their application in the addition of diethylzinc to aldehydes.

The straightforward preparation of new modular oxazoline-containing bifunctional catalysts is reported employing a microwave-assisted Buchwald-Hartwig aryl amination as the key step. Covalent attachment of 2-(o-aminophenyl)oxazolines and pyridine derivatives generated in good-to-high yields a series of ligands in two or three steps in which each part was altered independently to tune the activi...

Concise synthesis of novel practical sulfamide-amine alcohols for the enantioselective addition of diethylzinc to aldehydes.

Novel sulfamide-amine alcohol ligands were designed using a grafting strategy and synthesized from readily available starting materials via a simple, efficient method. The key features of these ligands for the asymmetric addition of diethylzinc to aldehydes included stability, enhanced effectiveness without using Ti(O(i)Pr)(4), suitability for a variety of aldehydes, the ability to operate at r...

Asymmetric Preparation of D-Phg-L-Pro Dipeptide-derived Chiral Ligands for Enantioselective Addition of Diethylzinc to Aldehydes