抄録
A design of a chiral ligand and the metal-coordinated catalyst is very important for achievement of a highly enantioselective catalytic asymmetric reactions. Recently, we developed the chiral oxazolidine ligands having N,O-acetal structure, such as phosphinooxazolidine (POZ), phosphinooxazinane (POZI) and oxazolidine (OZ). POZ and POZI afforded products in an excellent enantioselectivities in Pd-catalyzed asymmetric allylic alkylation and tandem allylation. Furthermore, cationic Pd-POZ catalysts showed high levels of catalytic activity in the asymmetric Diels-Alder (DA) reactions of some dienes with oxazolidinone- or pyrrazolidinone-type dienophiles. Cationic Pd-POZ catalyst showed an excellent catalytic activity in the DA reaction in ionic liquid (IL). The catalyst could be reused eight times without significant decrease of yield and enantioselectivity in IL/CH2Cl2 solvent system. OZ ligand also worked as organocatalyst in the DA reaction of 1,2-dihydropyridies with acroleins to afford the useful intermediate of Oseltamivir.
