Study On The Carbonylation Of ?,?-Difluoromethylene-?-Allen Phosphonate Catalyzed By Metal Palladium

Both the fluorinated phosphates and the ?,?-unsaturated carbonyl compounds are important units in many biologically active natural products.In addition,many of them showed good biological activities and were used as medicines and pestcides.By now much more attentions have been focused on the development of new methodologies for the synthesis of the fluorinated phosphates and ?,?-unsaturated carbonyl compounds.The transition-metal catalyzed carbonylation of fluorine-containing allenic phosphonates are proven to be an effective way for synthesis of these compounds.This dissertation is carried out on the basis of our previous research.The dissertation consists of two parts:Firstly,the palladium-catalyzed hydroacylation of the ?,?-difluoromethylene-?-allenic phosphonates with aromatic acid chlorides were studied.The reactions proceeded with Pd(OAc)2 as a catalyst,HSi(i-Pr)3 as a reducing reagent and Ag2CO3 as additive,giving the corresponding?,?-difluoromethylcnephononates containing ?,?-unsaturated ketones with good yield and regio-selectively.Secondly,the palladium-catalyzed hydrocsterification of the ?,?-difluoromethyl ene-?-allenic phosphonates with aryl formats as a new carbonyl source were studied.The hydroesterification proceeded with the Pd(PPh3)4 as a catalyst and subsequently underwent defluorination,affording a new series of ?,?-unsaturated esters containing a-fluorovinylphosphonates unit with high yields and good regio and stereoselectivity.These methodologies provide easy ways to synthesize fluorine-containing phosphonate mimics with potential biological activities.