2,2′-Bis(diphenylphosphino)biphenyl revisited

The reaction between 2,2'-dilithiobiphenyl and two equiv. of chlorodiphenylphosphine is confirmed to afford equal amts. of 9-phenyl-9-phosphafluorene (2) and PPh3. 2,2'-Bis(diphenylphosphino)biphenyl (1,1'-biphenyl-2,2'-diylbis(diphenylphosphine) (1)) can be conveniently prepd. by Ullmann coupling of 2-iodophenyldiphenylphosphine oxide and subsequent redn. with trichlorosilane. [on SciFinder (R)]