Franco Soccolini

Optically active nitrogen ligans: III. Enantioface-discriminating transfer hydrogenation of acetophenone catalyzed by rhodium(I) complexes with chiral 2-(2′-pyridyl)pyridines

Abstract The reduction of acetophenone by hydrogen transfer from isopropranol is catalyzed by rhodium(I) complexes containing optically active 2-(2′-pyridyl)pyridines. Optical yields up to 15% have been obtained.

Diastereoisomeric pure 2-(1-hydroxyalkyl)pyridines as catalysts in the enantioselective addition of diethylzinc to aldehydes

Abstract Diastereoisomeric pure 2-(1-hydroxyalkyl)pyridines have been prepared from chiral ketones and checked as enantioselective catalysts in the addition of diethylzinc to aldehydes: enantioselectivities up to 82% were obtained.

Optically active phenanthrolines in asymmetric catalysis. II: Enantioselective transfer hydrogenation of acetophenone by rhodium/alkyl phenanthroline catalysts

Abstract Three new alkyl phenanthrolines containing a norpinanyl substituent as the common chiral target, have been synthesized and tested as ligands in the rhodium-catalyzed asymmetric transfer hydrogenation of acetophenone. A marked catalytic activity was observed, but the highest optical yield was 24% e.e.

Chiral 2,2′-bipyridines, 5,6-dihydro-1,10-phenanthrolines and 1,10-phenanthrolines as ligands for enantioselective palladium catalyzed allylic substitution

Abstract A number of chiral 5,6-dihydro-1,10-phenanthrolines, 5,6-dihydrobenzo[b]-1,10-phenanthrolines and 5,6,7,8-tetrahydro-2-quinolinylquinolines derived from (−)-pinocarvone were prepared and assessed in the enantioselective palladium catalyzed allylic alkylation of 1,3-diphenylprop-2-enyl acetate with dimethylmalonate. The introduction of a benzo-fused substituent on the pyridine ring not containing the chiral backbone resulted in the drastic reduction of the stereoselectivity of the reaction. Enantioselectivities up to 81% were obtained.

Chiral 2-(2-diphenylphosphinophenyl)-5,6,7,8-tetrahydroquinolines: new P–N ligands for asymmetric catalysis

Abstract New chiral phosphorus–nitrogen ligands, specifically, 2-(2-diphenylphosphinophenyl)-5,6,7,8-tetrahydroquinolines were prepared and assessed in the enantioselective palladium catalyzed allylic substitution of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate. Enantioselectivity up to 71% was obtained.

Optically active phenanthrolines in asymmetric catalysis. Rhodium-catalyzed asymmetric transfer hydrogenation of acetophenone

Abstract The catalyst formed in situ from [Rh(1,5-cyclooctadiene)Cl]2 and (+)-(S)-3-s-butyl-1,10-phenanthroline promotes the asymmetric transfer hydrogenation of acetophenone in isopropanol solution; optical yields of up to 31% are obtained.

Cyclopropanation of styrene with diazoacetates catalyzed by copper and rhodium complexes of new chiral 2,2' :6', 2-terpyridines derived from natural occurring compounds

Abstract Three new chiral 2,2′:6′,2″-terpyridines (terpy) were prepared from (−)-β-pinene, (+)-camphor and (+)-2-carene and the corresponding copper and rhodium complexes were assessed as chiral catalysts for the enantioselective cyclopropanation of styrene with diazoacetates. Enantioselectivities up to 64% were obtained.

Optically Active Nitrogen Ligands. II. Synthesis of (-)-S-3-sec-Butyl- and (+)-S-5-sec-Butyl-2-(2′-Pyridyl)Pyridine

Abstract Syntheses of optically active (-)-S-3-sec-butyl- and (+)-S-5-secbutyl-2-(2′-pyridyl)pyridine are described. The value of the maximum rotatory power for both compounds is reported.

Chiral thienylpyridines as N–S ligands for asymmetric catalysis: Palladium-catalyzed allylic alkylation and copper-catalyzed cyclopropanation reactions

Diastereomeric pure thienylpyridines were prepared and assessed in the enantioselective palladium-catalyzed allylic substitution of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate and copper-catalyzed cyclopropanation of styrene with ethyl diazoacetate. These ligands provided unreactive palladium catalysts but effective copper catalysts affording however low enantioexcesses.

Chiral 8-substituted 2-(2-methoxyphenyl) and 2-(2-hydroxyphenyl)-5,6,7,8-tetrahydro-6,6-dimethyl-5,7-methanoquinolines as ligands for enantioselective catalysis: palladium catalyzed allylic substitution and addition of diethylzinc to benzaldehyde

Diastereomeric pure 8-substituted 2-(2-methoxyphenyl) and 2-(2-hydroxyphenyl)-5,6,7,8-tetrahydro-6,6-dimethyl-5,7-methanoquinolines were prepared and assessed in the enantioselective palladium catalyzed allylic substitution of 1,3-diphenylprop-2-enyl acetate with dimethyl malonate and addition of diethylzinc to benzaldehyde. Enantioselectivity up to 61% was obtained.