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Trisubstituted in chlorides react with (α-lithioalkyl)phosphonates, in the presence of one equivalent of lithium diisopropylamide, to give after protonation or alkylation the dialkyl 1-(triorganostannyl)alkylphosphonates in excellent yields

Diethyl 2,4-dioxoalkylphosphonates are prepared in excellent yields by Claisen condensation of the dianion of diethyl 2-oxoalkylphosphonates with ethyl esters or acyl chlorides in the presence of one equivalent of lithium diisopropylamide (LDA).

We find that 1 equiv. of NaI greatly accelerates the photostimulated substitution (S RN 1 mechanism) of bromobenzene, bromotoluenes and bromopyridines by diethylphosphite ion, in acetonitrile/tetrahydrofuran mixtures. Consequently, bromoaromatic compounds are suitable for preparative use.

Diisopropyl 1,1-dichloroalkylphosphonates bearing various groups (alkyl, aryl, allyl, benzyl, phenylthiolate, trimethylsilyl) in the α-position were reduced to the corresponding primary 1,1-dichlorophosphines by the LiAlH4-AlCl3 system in diethyl ether. Subsequent dehydrochlorination with tertiary amines in the presence of trapping dipolar compounds (ethyl diazoacetate or n-hexylazide) led to the expected 1,2,4-diazaphospholes or 3H-1,2,3,4-triazaphospholes.

The treatment of some diethyl (α-allyloxymethyl)phosphonates with two equivalents of lithium diisopropylamide at − 70°C in THF led, after hydrolysis, to the corresponding (α-hydroxy-α-allylmethyl)phosphonates resulting of [2,3]-Wittig rearrangement of α-metallated starting phosphonates.

Various diisopropyl 1,1-dichloroalkylphosphonates were easily and rapidly prepared under mild conditions, by electrolysing, in DMF medium, diisopropyl trichloromethylphosphonate in the presence of alkylating reagents. The use of an electrochemical activated magnesium anode significantly improved the rate and the yield of the reaction.

Various diisopropyl cycloalkylphosphonates were easily prepared in an one-pot sequence under mild conditions, by electrolysing diisopropyl trichloromethylphosphonate in the presence of ω,ω-dibromoalkanes. The use of an electrochemical activated magnesium amode significantly improved the rate and the yield of the two first steps of the reaction.

A study of the reactivity of ylides of α-allylamino and α-allylthio-methyl-phosphonates and a comparison with the reactivity of the corresponding carbanions demonstrate the complementarity of these intermediates for the preparation of α-heteroatom-substituted alkenylphosphonates via [2,3]-sigmatropic rearrangements.

Diethyl (E)-alkenylphosphonates have been prepared stereoselectively by dehydration of the corresponding β-hydroxyphosphonates using DCC/CuCl2 in refluxing toluene. Starting β-hydroxyphosphonates were obtained in high yield from diethyl methylphosphonate.

An efficient carbanionic synthesis of the phosphonic dicarbonylated compounds 2 was achieved and used as key intermediates in the synthesis of the phosphonic furans 4 by acid-induced Paal-Knorr cyclization reaction.

The diastereoselective electrosynthesis of polysubstituted α-chloro cyclopropylphosphonates is efficiently achieved by electroreduction of diisopropropyl trichloromethylphosphonate in the presence of Michael acceptors, in a one-compartment cell equipped with a magnesium sacrificial anode.

When treated with electrophilic m-CPBA reagent, dienes 1 were efficiently epoxidized at the silylated 1,2-double bond exclusively. Otherwise, regioselective cyclopropanation of the phosphonylated 3,4-double bond was achieved by using the nucleophilic Corey's reagent. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10:231–236, 1999

Variously substituted α-carbonylated styrylphosphonates 5 were easily prepared by Knoevenagel-type syntheses, and used as oxadienes in hetero-Diels–Alder [4 + 2] cycloadditions with enol ethers, to give new phosphonylated 3,4-dihydro-2H-pyrans 6. It was confirmed that the reactivity , as well as the trans-diastereoselectivity of the reaction, was significantly enhanced by the use of high-pressure conditions, particularly in the presence of ButOH as a co-solvent. Moreover, a one-pot synthesis of 6 via a tandem-sequence Knoevenagel and hetero-Diels–Alder reactions was achieved.