Ambient temperature hydrophosphination of internal, unactivated alkynes and allenyl phosphineoxides with phosphine borane complexes.
Phosphine boranes have been found to hydrophosphinate internal, unactivated alkynes at room temperature under basic conditions without the need for catalysts or radical initiators. The use of air-sensitive secondary phosphines is avoided in this facile process. Broad scope in both the phosphine borane and alkyne partners leads to excellent diversity in the phosphine products. Asymmetric hydrogenation of these species then provides one of the shortest possible routes to chiral monodentate phosphines. Hydrophosphination of allenyl phosphine oxides under similar conditions followed by hydrogenation of the exomethylene moiety yields a wide variety of bis-phosphine derivatives.
Busacca
Carl A
CA
Department of Chemical Development, Boehringer-Ingelheim Pharmaceuticals, Inc., 900 Ridgebury Road, Ridgefield, Connecticut 06877, USA. carl.busacca@boehringer-ingelheim.com
Farber
Elisa
E
Deyoung
Jay
J
Campbell
Scot
S
Gonnella
Nina C
NC
Grinberg
Nelu
N
Haddad
Nizar
N
Lee
Heewon
H
Ma
Shengli
S
Reeves
Diana
D
Shen
Sherry
S
Senanayake
Chris H
CH
D000480:Alkynes / Q000737:chemistry*; D001880:Boranes / Q000138:chemical synthesis* / Q000737:chemistry; D020650:Combinatorial Chemistry Techniques; D006865:Hydrogenation; D015394:Molecular Structure; D010720:Phosphines / Q000138:chemical synthesis* / Q000737:chemistry; D013696:Temperature
D000480:Alkynes; D001880:Boranes; D010720:Phosphines