Electron-Deficient Diphosphines: The Impact of DIFLUORPHOS in Asymmetric Catalysis

Iridium/copper-cocatalyzed asymmetric ring opening reaction of azabenzonorbornadienes with amines

“…Encouraged by this good result, a range of chiral diphosphine ligands were investigated. 10 Almost same ees (86-88%) were obtained when using (R)-SDP, (R)-Tol-SDP, or (R)-Xyl-SDP as ligand, while (R)-Xyl-SDP could give a better yield (96%) ( The addition of Lewis acid is crucial for higher yield and enantioselectivity. When the reaction was carried out in the absence of CuI, only 51% yield and 86% ee were obtained (Table 2, entry 1).…”

(R)- and (S)-2,2′-Bis(diphenylphosphino)-6,6′-dimethoxy-1,1′-biphenyl

“…73 Enantiomeric excess values up to 94% were achieved with DIFLUORPHOS as the chiral diphosphine. 74 The same catalyst has been reported to promote the asymmetric hydrogenation of 7, The Ir-MeOBIPHEP-catalyzed asymmetric hydrogenation of quinolinium salts with Bronsted acids (e.g., TfOH.py) has been reported to afford the corresponding tetrahydroquinolines with 86% ee. Slightly higher ee values were obtained with SEGPHOS.…”

The Future of Catalysis by Chiral Lewis Acids

“…Diels-Alder reactions were among the first to be investigated with chiral Lewis acids [26][27][28][29][30][31], but it has been the hetero-Diels-Alder reactions that have commanded the most attention [24,[32][33][34][35][36][37]. With normal Diels-Alder reactions that form cyclohexene structures, activation of the dienophile by Lewis acid coordination lowers the LUMO dienophile energy which causes an increase in the rate of reaction, and positioning of a Lewis acid on a heteroatom near to the reacting dienophile (as in acrylates) affects stereocontrol.…”