Synthesis and structures of cis- and trans-bis(allenyl)cylclodiphosph(V)azanes and a bis(allyl)cyclodiphosph(V)azane

Abstract

The bis-(allenyl)phosphoramidates cis-[(H2C{double bond, long}C{double bond, long}CH)(O)P(μ-N-t-Bu)]2 (9), cis- and trans-[(Me2C{double bond, long}C{double bond, long}CH)(O)P(μ-N-t-Bu)]2 (10a,b) and cis- and trans-[((Me)(Et)C{double bond, long}C{double bond, long}CH)(O)P(μ-N-t-Bu)]2 (11a,b) based on a cyclodiphosph(V)azane skeleton have been synthesized by treating cis-[ClP(μ-N-t-Bu)]2 (1) with the respective propargylic alcohol in the presence of triethylamine. The Baylis-Hillman adduct PhCH(OH)C(CO2Me){double bond, long}CH2 also reacts with 1 to lead to the bis-(allyl)phosphoramidate cis-[((Ph)HC{double bond, long}C(CO2Me)-CH2)(O)P(μ-N-t-Bu)]2 · H2O (13 · H2O). In this case, a 31P NMR study shows that yet another P(V) compound, tentatively assigned the trans-structure, was initially formed. Preliminary calculations suggest that the cis-isomer 10a is slightly more stable than the trans-isomer 10b in the gas phase. The structures of 9, 10a,b and 13 · H2O are confirmed by X-ray crystallography. © 2006 Elsevier Ltd. All rights reserved.