Studies On Sp~3C-P Bonds Formation Via Conversion Of P(O)-H Bonds

Organophosphorus compounds containing sp3C-P bond are widely used in medicine,pesticide,and industrial catalysis.Cross-coupling reactions between P(O)-H compounds and other coupling partners are one of the most effective methods for constructing sp3C-P bonds.In this thesis,a cross-coupling reaction between P(O)-H bonds and C-O bonds for the synthesis of a-alkoxyphosphorus compounds and a cross-dehydrogenation-coupling reaction between P(O)-H bonds and C-H bonds for the phosphorylation of isochromans have been developed.The contents and the results come as follows:(1)A new method for the preparation of a-alkoxyphosphorus compounds via iron-catalyzed P-H/C-O cross coupling has been developed.This transformation could proceed efficiently with a ligand free and environmentally benign iron catalytic system to produce the corresponding a-alkoxyphosphorus compounds in high yields from the easily available P-H compounds and acetals with a wide generality.A lot of functional groups like ester,ether,F,Cl,Br,I and NO2 all could be tolerated well in the present system.The three kinds of hydrogen phosphoryl compounds,i.e.H-phosphonates,H-phosphinates and secondary phosphine oxides all could serve as good substrates and be converted to the corresponding coupling products.(2)An efficient P-H/C-H cross-dehydrogenation-coupling reaction for constructing sp3C-P bonds was achieved for the first time under the metal-free reaction conditions.By using K2S2O8 as the oxidant,a variety of isochromans coupled readily with hydrogen phosphoryl compounds,producing the expected phosphorylated products in moderate to good yields.This transformation provides an efficient method for the phosphorylation of isochromans.