Synthesis of anionic phosphorus-containing heterocycles by intramolecular cyclizations involving N-functionalized phosphinecarboxamides.
We report that the 2-phosphaethynolate anion (PCO(-)) reacts with propargylamines in the presence of a proton source to afford novel N-derivatized phosphinecarboxamides bearing alkyne functionalities. Deprotonation of these species gives rise to novel five- and six-membered anionic heterocycles resulting from intramolecular nucleophilic attack of the resulting phosphide at the alkyne functionality (via 5-exo-dig or 6-endo-dig cyclizations, respectively). The nature of the substituents on the phosphinecarboxamide can be used to influence the outcome of these reactions. This strategy represents a unique approach to phosphorus-containing heterocylic systems that are closely related to known organic molecules with interesting bio-active properties.
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA (UK).
Thomas P
TP
Robinson
Jose M
JM
Goicoechea
2-phosphaethynolate anion; heterocycles; phosphides; phosphorus; propargyl-phosphines