Highly Enantioselective Conjugate Additions of Potassium Organotrifluoroborates to Enones by Use of Monodentate Phosphoramidite Ligands

Highly enantioselective conjugate additions of potassium organotrifluoroborates to enones by use of monodentate phosphoramidite ligands.

The use of phosphoramidite ligands in the rhodium-catalyzed asymmetric conjugate addition of potassium organotrifluoroborates to various enones in the absence of water is described. A systematic search for effective catalysts has been performed by use of high-throughput screening methods. Initially, we have screened reaction conditions, catalyst precursors, and focused ligand libraries. In the ...

Highly enantioselective copper(I)-phosphoramidite-catalysed additions of organoaluminium reagents to enones.

Simple phosphoramidite ligands afford good to excellent levels of enantioselectivity in 1,4-additions of AlR3 species to enones; sequential carboalumination-ACA cascades are possible.

Enantioselective gold catalysis: opportunities provided by monodentate phosphoramidite ligands with an acyclic TADDOL backbone.

Asymmetric hydrogenation using monodentate phosphoramidite ligands.

Monodentate phosphoramidites are excellent ligands for Rh-catalyzed asymmetric hydrogenations of substituted olefins. Enantioselectivities between 95 and 99% were obtained in the asymmetric hydrogenation of protected alpha- and beta-dehydroamino acids and esters, itaconic acid and esters, aromatic enamides, aromatic enol esters, aromatic and aliphatic enol carbamates, and alpha-substituted cinn...

Synthesis and evaluation of guanidinyl pyrrolidines as bifunctional catalysts for enantioselective conjugate additions to cyclic enones.

Guanidinyl pyrrolidines derived from 'S'-proline are effective catalysts for the enantioselective conjugate addition of malonate, nitroalkane and other carbon and heteroatom nucleophiles to cyclohexenone and cyclopentenone in the absence of basic additives. The stereoselectivity is strongly dependent on catalyst loading as well as reaction concentration.