TADDOL-derived phosphites and phosphoramidites for efficient rhodium-catalyzed asymmetric hydroboration.
[reaction: see text] Two simple TADDOL-derived monodentate ligands, the (1R,2S)-2-phenylcyclohexanol-derived phosphite and the N,N-(phenylbenzyl)phosphoramidite, give comparably high levels of enantioselectivity (90-96% ee) in the rhodium-catalyzed hydroborations of substituted styrenes bearing either electron-donating or electron-withdrawing substituents. Rhodium(I) chloride and tetrafluoroborate catalyst precursors give comparable results. Pinacolborane is superior to catecholborane in these reactions.
Moteki
Shin A
SA
Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, 68588, USA.
Wu
Di
D
Chandra
Kusum L
KL
Reddy
D Sahadeva
DS
Takacs
James M
JM
D001880:Boranes / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D004148:Dioxolanes / Q000737:chemistry*; D000432:Methanol / Q000031:analogs & derivatives* / Q000737:chemistry; D015394:Molecular Structure; D009943:Organophosphorus Compounds / Q000737:chemistry*; D017905:Phosphites / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013343:Styrenes / Q000737:chemistry
D001880:Boranes; D004148:Dioxolanes; D009943:Organophosphorus Compounds; D017905:Phosphites; D013343:Styrenes; C516101:alpha,alpha,alpha',alpha'-tetraaryl-1,3-dioxolane-4,5-dimethanol; C434331:phosphoramidite; D012238:Rhodium; D000432:Methanol