Acetylene Phosphonates as Dienophiles: A Route to Carbocyclic and Aromatic Phosphonates and Diphos-Phonates |
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Authors: | A V Dogadina A I Senderickhin B I Ionin A A Petrov |
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Institution: | Leningrad Lensoviet Institute of Technology , Leningrad , 198013 , USSR |
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Abstract: | Abstract Systematic research of unsaturated phosphonates, started at the end of the sixties, gave rise to a variety of acetylene phosphonic derivatives. The authors worked out two significant routes to these compounds, (1) action of PCl5 upon some alkynes followed by HCl elimination which gives alkyne dichlorophosphonates. and (2) Arbuzov reaction of PIII esters with halo- and dihaloalkynes which gives different phosphono- and diphosphonoacetylenes. The phosphonic groups are electron-withdrawing, and acetylenephosphon-ates are typical dienophiles in Diels-Alder cycloaddition of diene-donor/dienophile-acceptor type. Phosphonic esters are less active than corresponding dichlorophosphonates, but diphosphonic esters expose high reactivity. Haloethyne- and dialkylaminoethynephosphonates are sufficiently active in the reaction with simple dienes (butadiene, iso-prene, 2,3-dimethylbutadiene and piperylene), but we were not able to introduce alkyl- or arylacetylene phosphonic esters in the cycloaddition. |
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