Stereoselective synthesis of new functionalized bisphosphines

New chiral monodentate phospholane ligands by highly stereoselective hydrophosphination

“…1 H NMR (C 6 D 6 ) d: 1.42-1.54 (m, 1H), 1.66-1.82 (m, 1H), 2.13-2.4 (m, 3H), 2.57-2.67 (m, 1H), 4.46 (t, J = 6.9 Hz, 1H), 4.77 (t, J = 6.6 Hz, 1H), 7.02-7.08 (m, 5H). 13 3.5. BH 3 complex of (3aS,4aS,7aS,7bS)-4-cyclohexylperhydrofuro[2 0 ,3 0 :4,5]phospholo [3,2-b]furan-2,6-dione 10b…”

“…14-5.35 (m, 2H). 13 To a solution of 10b (0.2 g, 0.69 mmol) in THF (10 ml) was added DABCO (81 mg, 0.72 mmol) and the mixture stirred at 55°C for 3 h. The solvent was evaporated and the phosphine purified on silica gel (CHCl 3 /MeOH, 20/1) to give 0.14 mg (75% yield) of phospholane 6b. Mp = 157°C.…”

“…15 It has been used by Le Corre et al for the synthesis of a related bis(diphenylphosphine) substituted chelating ligand. 13 However, the analogous reaction of monophosphine-borane complexes is less studied. 16 In this case, hydrophosphination is mostly accompanied by hydroboration and decomposition of the rather unstable phosphine-boranes.…”

“…The key transformation is the double hydrophosphination reaction between phenylphosphine-borane adduct and bis(lactone) 9. The latter was prepared according to a protocol by Le Corre et al 13 Diester 8 representing the direct precursor of 9 was obtained following a known procedure. 14 The published procedure for the formation of 9 implies the isolation of the Z,Z-isomer of 8, but we found that the use of the diastereomeric mixture of 8 for the lactonization also led to pure bis(lactone) 9 in 26% overall yield from 7.…”

Synthesis and Coordination Chemistry of Cyano-Substituted Phosphines

“…Thus, a substituted analogue of DIOP ligand 33 was obtained via a stereospecific addition of diphenylphosphine borane adduct to a mixture of diolefin isomers 32 (Scheme 32) [52].…”