Application of AMPP-Pd catalysts in an unusual asymmetric allylic coupling reaction of 1-trimethylsilyl vinyl magnesium bromide

Copper-catalyzed asymmetric allylic substitution with aryl and ethyl Grignard reagents

Phenyl- and ethyl-magnesium bromides undergo regioselective asymmetric allylic substitution with high enantioselectivity under the catalysis of chiral amidophosphane-copper(I) complexes.

Iridium-catalyzed asymmetric allylic substitution with aryl zinc reagents

Thanks to iridium catalysis, arylzinc reagents undergo regioselective allylic substitution with very high enantioselectivity, when associated with phosphoramidite ligands.

Highly enantioselective Cu-catalysed allylic substitutions with Grignard reagents

A catalyst system able to perform highly enantioselective Cu-catalysed allylic alkylations with Grignard reagents is described.

DELETEile chiral bidentate ligands derived from alpha-amino acids: synthetic applications and mechanistic considerations in the palladium-mediated asymmetric allylic substitutions

A new class of chiral amidine-phosphine hybrid ligands 7a,b, which are readily accessible from the corresponding alpha-amino acids, were developed. A versatility for construction of new ligands is desirable, by which a variety of reactions and substrates become applicable. Indeed, a variety of modifications, such as exchange reactions to other amino groups in the amidine skeleton and the production of other types of ligands, are possible using the precursor compounds of 7a. Thus, novel chiral ligands 7c,d, 8, 11, and 13, which provide sterically and electronically different chiral circumstances, were prepared and used for the palladium-mediated asymmetric allylic substitutions of both acyclic and cyclic compounds. In these reactions, high levels of asymmetric induction were achieved for both substrates. A marked advancement of reactivity and enantioselectivity in palladium-catalyzed asymmetric allylations of 1,3-diphenylpropen-2-yl pivalate 14a was attained by examination of electronic substituent effects in a new series of chiral P-N and S-N hybrid ligands 8 and 11. Mechanistic views concerning the enantiodiscriminating step were demonstrated, in which a good correlation between a novel Pr/Mr concept and the absolute configuration of allylation products are discussed for the prediction of enantioselecting direction. The use of ketene silyl acetals as nucleophiles was investigated and compared with the corresponding harder anionic carbon nucleophiles. The former nucleophiles afforded higher enantioselectivity in asymmetric allylic transformations of 14a.