Enantioselective hydroformylation of N-vinyl carboxamides, allyl carbamates, and allyl ethers using chiral diazaphospholane ligands.
Rhodium complexes of diazaphospholane ligands catalyze the asymmetric hydroformylation of N-vinyl carboxamides, allyl ethers, and allyl carbamates; products include 1,2- and 1,3-aminoaldehydes and 1,3-alkoxyaldehydes. Using glass pressure bottles, short reaction times (generally less than 6 h), and low catalyst loading (commonly 0.5 mol %), 20 substrates are successfully converted to chiral aldehydes with useful regioselectivity and high enantioselectivity (up to 99% ee). Chiral Roche aldehyde is obtained with 97% ee from the hydroformylation of allyl silyl ethers. Commonly difficult substrates such as 1,1- and 1,2-disubstituted alkenes undergo effective hydroformylation with 89-97% ee and complete conversion for six examples. Palladium-catalyzed aerobic oxidative amination of allyl benzyl ether followed by enantioselective hydroformylation yields the β(3)-aminoaldehyde with 74% ee.
McDonald
Richard I
RI
Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, Wisconsin 53706, USA.
Wong
Gene W
GW
Neupane
Ram P
RP
Stahl
Shannon S
SS
Landis
Clark R
CR
D000577:Amides / Q000737:chemistry*; D001372:Aza Compounds / Q000737:chemistry*; D002219:Carbamates / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry*; D008024:Ligands; D013237:Stereoisomerism
D000577:Amides; D001372:Aza Compounds; D002219:Carbamates; D004987:Ethers; D008024:Ligands