Regio- and Enantioselective Allylic Cyanomethylation by Synergistic Rhodium and Silane Catalysis

Abstract

Rh/silane-cocatalyzed regio- and enantioselctive allylic cyanomethylation with inert acetonitrile directly has been developed. Addition of a catalytic amount neutral silane reagent as an acetonitrile anion carrier is essential for the success of this reaction. The synthesis of mono- and bis-allylation products can be switched by adjusting the size of substituents on the silane, ligands, and temperature. Chiral homoallylic nitriles could be synthesized in above 20:1 branch/linear ratio, up to 98% yield and >99% ee.

Rh-Catalyzed Asymmetric Allylic Substitution with Photo-Generated Alkyl Radical Species

“…have conducted pioneering studies. Recently, the Li group made great contribution into Rh-catalyzed AAS reactions by employing a Rh-bisoxazolinephosphine (NPN) catalyst . The crucial chiral π-allyl-Rh(III)/NPN intermediate was further characterized, elucidating the origin of the high enantioselectivity .…”

Rhodium-Catalyzed Tandem Asymmetric Allylic Decarboxylative Addition and Cyclization of Vinylethylene Carbonates with N-Nosylimines

“…Since Hayashi [ 6 ] reported the first Rh-catalyzed asymmetric allylic alkylation employing a bidentate N , P -ligand in 2003, a variety of bidentate ligands has been discovered or designed to succeed in the asymmetric allylic substitution reaction [ 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. Recently, Li [ 15 , 16 , 17 , 18 , 19 ] developed a Rh/ N , P , N -tridentate ligand [ 20 ] catalysis system, which has proven to be a powerful tool for catalyzing asymmetric allylic alkylation (AAA) reaction. A broad spectrum of nucleophiles including C, N, O, S, and even P [ 21 ] are compatible, showing a vigorousness of the tridentate ligand for allylic reaction ( Scheme 1 a).…”

Rhodium-Catalyzed Tandem Asymmetric Allylic Decarboxylative Addition and Cyclization of Vinylethylene Carbonates with N-nosylimines

“…Since Hayashi [6] reported the first Rh-catalyzed asymmetric allylic alkylation employing a bidentate N,P-ligand in 2003, a variety of bidentate ligands has been discovered or designed to succeed in the asymmetric allylic substitution reaction [7][8][9][10][11][12][13][14]. Recently, Li [15][16][17][18][19] developed a Rh/N,P,N-tridentate ligand [20] catalysis system, which has proven to be a powerful tool for catalyzing asymmetric allylic alkylation (AAA) reaction. A broad spectrum of nucleophiles including C, N, O, S, and even P [21] are compatible, showing a vigorousness of the tridentate ligand for allylic reaction (Scheme 1a).…”