The First Examples of Enantiomerically Pure Diphosphane Dioxides—(RP,RP)- and (SP,SP)-1,2-Di-ter-butyl-1,2-diphenyldiphosphane 1,2-Dioxides, and (RP)- and (SP)-1-tert-Butyl-1,2,2-triphenyldiphosphane 1,2-Dioxides
作者:Richard K. Haynes、William Wai-Lun Lam、Ian D. Williams、Lam-Lung Yeung
DOI:10.1002/chem.19970031221
日期:1997.12
AbstractWhereas oxidative dimerization of each of the lithiated reagents (RP)‐ and (SP)‐tert‐butylphenylphosphane oxides 1 Li and 2 Li by means of oxygen in THF at low temperature led cleanly to meso‐1,2‐di‐tert‐butyl‐1,2‐diphenyldiphosphane dioxide (3), the respective nucleophilic substitution reactions of 1 Li and 2 Li with the (RP)‐ and (SP)‐tert‐butylphenylphosphinic bromides (4 and 6) in THF under argon led to the corresponding (SP,SP)‐ and (RP,RP)‐12‐di‐tert‐butyl‐1,2‐diphenyldiphosphane dioxides (5 and 7) in good yields, together with the meso‐diphosphane dioxide 3. The structures of 3 and 5 were established by X‐ray crystallography. Similarly, the reaction of lithiated (RP)‐phosphane oxide 1 Li with diphenylphosphinic bromide (8) or of achiral lithiated diphenylphosphane oxide 10 Li with (RP)‐tert‐butylphenylphosphinic bromide (4) provided (SP)‐tert‐butyltriphenyldiphosphane dioxide (9).