134435-28-2Relevant academic research and scientific papers
Switching on and off metalation sites in triarylphosphines by manipulating substrate coordination
Desponds, Olivier,Huynh, Cyril,Schlosser, Manfred
, p. 983 - 985 (1998)
The inductive electron-withdrawing effect of the positively charged phosphorus atom in triarylphosphine-borane adducts is largely compensated by the steric congestion caused in its vicinity. Therefore, trihydro(triphenylphosphonio)borate reacts only sluggishly even with superbasic reagents and products derived from ortho-metalated intermediates by their trapping with electrophiles are formed only in poor yield. On the other hand, the borane adducts of (3-anisyl)diphenylphosphine and (3- fluorophenyl)diphenylphosphine can be readily deprotonated at the hetero- adjacent para position and converted into final products in high yields. The phosphorus-remote regioselectivity of these phosphine-borane zwitterions is complementary to that previously observed with the corresponding phosphine oxides.
Axially Dissymmetric Diphosphines in the Biphenyl Series: Synthesis of (6,6'-Dimethoxybiphenyl-2,2'-diyl)bis(diphenylphosphine) ('MeO-BIPHEP') and Analogues via an ortho-Lithiation/Iodination Ullmann-Reaction Approach
Schmid, Rudolf,Foricher, Joseph,Cereghetti, Marco,Schoenholzer, Peter
, p. 370 - 389 (2007/10/02)
The new axially dissymmetric diphosphines (R)- and (S)-(6,6'-dimethoxybiphenyl-2,2'-diyl)bis(diphenylphosphine) ((R)- and (S)-5a; 'MeO-BIPHEP') and the analogues (R)- and (S)-5b and 5c have been synthesized in enantiomerically pure form.These lignands hav
