Phosphorus heterocycle synthesis using RPX2·AlX3 addition to 1,4-dienes—1

Cheletropic Reactions

“…On the other hand, the results are also not in accord with expectation for a long-lived diradical (Kellogg and Prins, 1974). Without specifically disputing previous interpretations, we wish to suggest an alternative explanation in which the invocation of orbital symmetry selection rules is deliberately avoided.…”

“…have been reported (Green, 1963;Kashman et al, 1973). The ozone-phosphite adduct (20) represents a formal example of cheletropy of a novel sort (Stephen son and McClure, 1973).…”

Ternary metal complexes of anionic and neutral pyridoxine (vitamin B6) with 2,2'-bipyridine. Syntheses and x-ray structures of (pyridoxinato)bis(2,2'-bipyridyl)cobalt(III) perchlorate and chloro(2,2'-bipyridyl)(pyridoxine)copper(II) perchlorate hydrate

“…Further support to this conclusion comes from the hydrogen-bonding pattern (vide infra). (48) In fact, pH-metric titration of 2.6 x 10™4 M [Co(bpy)2(PN-H)](C104)2 in the pH range [3][4][5][6][7][8][9][10][11] shows that there are two deprotonation steps. In the first step corresponding to deprotonation at phenolic O (pH range 4-6.5; p«= 4.45) 1 mol of sodium hydroxide/mol of the compound is consumed, whereas in the second step (pH range 6.5-10; pÁfa = 6.85), which is quite steep when compared to that of free PN, 2 mol of the base/mol of the compound is consumed.…”

“…Phosphenium ions have, in fact, been postulated as intermediates in the McCormack reaction of dichlorophosphines with 1,3-dienes.3 A somewhat stronger case for their intermediacy stems from the fact that complexes of the type RPX2-A1X3 (R = Me, Ph; X = Cl, Br) are reactive toward 1,4-dienes. 4 In view of the foregoing, it was of interest to determine whether stabilized phosphenium ions would react with 1,3-and/or 1,4-dienes. Moreover, as recognized by SooHoo and Baxter5 and ourselves,6 ***the diene/ phosphenium ion reaction represents a potentially useful and convenient synthetic route to phosphorus heterocycles.…”

Polycyclic carbon-phosphorus heterocycles

“…For example, addition of phenylphosphine to propenyl cyclohexenyl ketone (31) gave a phosphadecalone 32 as an inseparable mixture of isomers. 200 Upon oxidation of the mixture with hydrogen peroxide, 2-phenyl-2-oxo-3-methylphosphabicyclo[4.4.0]decan-5-one (33a) was obtained as a crystalline solid, mp 178-180 °C. The Me 31 33a, R = H b, R = D structural assignment was based on the 1H NMR spectrum of the trideuterio compound 33b, prepared by treating the oxide 33a with NaOD in CH3OD, coupled with mass spectral analysis of 33b.…”