Palladium-catalyzed reactions of hypophosphorous compounds with allenes, dienes, and allylic electrophiles: methodology for the synthesis of allylic h-phosphinates.
Hypophosphorous compounds (MOP(O)H(2), M = H, R(3)NH) effectively participate in metal-catalyzed C-P bond-forming reactions with allenes, dienes, and activated allylic electrophiles under mild conditions. The catalytic system Pd(2)dba(3)/xantphos is crucial to avoid or minimize the competitive reductive transfer-hydrogenation pathway available to hypophosphorous acid derivatives. Further investigation into the allylation mechanism provided access to the analogy allylic acetate-allylic phosphinate, which then led to the development of a Pd-catalyzed rearrangement of preformed allylic phosphinates esters and, ultimately, to a catalytic dehydrative allylation of hypophosphorous acid with allylic alcohols. The reactions disclosed herein constitute efficient synthetic approaches, not only to prepare allylic H-phosphinic acids but also their esters via one-pot tandem processes. In addition, the potential of H-phosphinates as useful synthons for the preparation of other organophosphorus compounds is demonstrated.
Bravo-Altamirano
Karla
K
Department of Chemistry, Box 298860, Texas Christian University, Fort Worth, Texas 76129, USA.
Abrunhosa-Thomas
Isabelle
I
Montchamp
Jean-Luc
JL
D000466:Alkadienes / Q000737:chemistry*; D000498:Allyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D010165:Palladium / Q000737:chemistry; D010721:Phosphinic Acids / Q000138:chemical synthesis*; D011090:Polyenes / Q000737:chemistry*; D020005:Propanols / Q000737:chemistry
D000466:Alkadienes; D000498:Allyl Compounds; D010721:Phosphinic Acids; D011090:Polyenes; D020005:Propanols; C006463:allyl alcohol; C025947:propadiene; D010165:Palladium