Dehydrogenative And Dehydrative Couplings Between Alcohols And P(O)-H Compounds Catalyzed By Iron Or Zinc

Organophosphorus compounds are widely used in organic synthesis,materials chemistry,pesticide,medicine,asymmetric catalysis.The use of base metals to initiate the cross-coupling reactions of P(O)-H compounds with other coupling reagents is one of the most desirable methods.Base metals,such as Fe,Zn,Cu,Mn,Co and so on,are rich in reserves,low cost and low toxicity.Especially,iron and copper not only have the reserves but also have high biocompatibility.P(O)-H compounds and alcohols are cheap,easily-handled and safe compounds which could serve as excellent coupling reagents.They meet the requirements of green chemistry.In this thesis,two new reactions were developed,i.e.a cross dehydrogenative coupling reaction between P(O)-H compounds and alcohols(phosphorylation of alcohols)and a cross dehydrative coupling between P(O)-H compounds and alcohols for the synthesis P-C bonds have been developed.The contents and the results come as follows:1.Preparation of organophosphorus compounds via iron-catalyzed dehydrogenative coupling of P(O)-H compounds with alcoholsAn iron-catalyzed cross dehydrogenative coupling of P(O)-H compounds with alcohols producing the corresponding organophosphorus compounds in good yields was described.This transformation has a good functional-group tolerance and various functional groups,such as methyl,methoxy,trifluoromethyl,halogen,cyano,thienyl and azomethyl were all tolerated well under this reaction conditions.A variety of alcohols efficiently coupled with P(O)-H compounds under similar reaction conditions to produce the corresponding phosphoryl compounds in good to high yields.The synthetic value of this new reaction was further demonstrated by the successful phosphorylation of(-)menthol and borneol.Thus,under similar iron-catalyzed CDC reaction conditions,both(-)menthol and borneol were phosphorylated with diphenylphosphine oxide to produce the corresponding phosphoryl compounds in high yield.This reaction was conducted under the halide and oxidant-free conditions and was deduced to generate dihydrogen.The generation of dihydrogen was confirmed by GC.At the same time,a kinetic isotope effect experiments were also carried out.The corresponding products were identified and a possible reaction mechanism was proposed.2.Preparation of organophosphorus compounds containing P-C bonds via zinc-catalyzed dehydrative coupling of P(O)-H compounds with alcoholsA Lewis acid-catalyzed(zinc-catalyzed)cross dehydrative coupling of P(O)-H compounds with alcohols producing the corresponding organophosphorus compounds containing P-C bonds was described.This transformation was performed under ligands,oxidant and halide-free conditions and appeared to be a simple,efficient and green method.Water is the only by-product in this dehydrative coupling reaction.Synthetically,such organophosphorus compounds are commonly prepared via the substitution reaction of a toxic halophosphoryl compound P(O)-X,directly or indirectly,with an alcohol ROH.This method shows great advantages.This transformation has a good functional-group tolerance that benzyl alcohol and 2-arylethanols with both electron-donating and electron-withdrawing groups on the benzene rings were successfully generated the corresponding products.