Paul A. Odorisio

12H-DIBENZO[d,g][1,3,2]DIOXAPHOSPHOCINS: Synthesis and Evidence for Long-Range Coupling to Phosphorus

Abstract The synthesis of the 12H-dibenzo[d,g][1,3,2]dioxaphosphocin ring system from 2,2′-alkylidene bisphenols and phosphorus trichloride is described. The 1H NMR shows evidence for long range through-space coupling of the C-12 methine proton to phosphorus.

The Reaction of Seven- and Eight- Membered Cyclic Phosphorochloridites with Polyols

Abstract The syntheses of novel bridged dibenzo[d,f][1,3,2]dioxaphosphepin and dibenzo[d,g][1,3,2]dioxaphosphocin ring systems are described. The 1H NMR spectral data of the eight-membered bridged dioxaphosphocins suggest the observation of a single conformational isomer. The 1H NMR spectrum of the dibenzo[d,g][1,3,2]dioxaborocin 5 requires that either a single nonplanar conformation is being observed or that ring inversion is slow on the NMR time scale. A lower limit of δG ‡ for ring inversion of 5 has been calculated to be 14.4 Kcal/mole. The 1H NMR of the C-12 methyl substituted dioxaphosphocins 4h-i showed the presence of a cis-trans isomer mixture.

REACTION OF SEVEN- AND EIGHT-MEMBERED CYCLIC PHOSPHOROCHLORIDITES WITH ALKANOLAMINES

Abstract The reactions of substituted 6-chloro-12H-dibenzo[d,g][1,3,2]dioxaphosphocins and 6-chlorodibenzo[d,f][1,3,2]dioxaphosphepins with primary, secondary and tertiary alkanolamines are described. The primary and sec-aminoalkyl phosphites prepared show no IR or NMR spectroscopic evidence for formation of their tautomeric pentacoordinate form.

REACTION OF SEVEN- AND EIGHT-MEMBERED CYCLIC PHOSPHOROCHLORIDITES WITH 3,5-DI-tert-BUTYL-4-HYDROXYBENZYL ALCOHOL: FACILE P[sbnd]C BOND FORMATION

Abstract The reaction of 2,4,8,10-tetra-t-butyl-6-chloro-12H-dibenzo[d,g][1,3,2]dioxaphosphocin (5) or 2,4,8,10-tetra-t-butyl-6-chloro-dibenzo[d,f][1,3,2]dioxaphosphepin (10) with 3,5-di-t-butyl-4-hydroxybenzyl alcohol (7) gave the corresponding P-(4-hydroxybenzyl)phosphonates 9 and 12 rather than the expected phosphites 8 and 11. IR and NMR spectral evidence for the phosphonate structure is discussed.

S-(Hydroxymethyl) 4-hydroxyphenyl sulfides: synthesis and selected chemistry of some stable hemimercaptals

Abstract The base-catalyzed reaction of 3,5-di-tert-butyl-4-hydroxybenzenethiol (1a), 3-tert-butyl-4-hydroxy-5-methylbenzenethiol (1b), and 4-hydroxybenzenethiol (1c) with formaldehyde gave the corresponding hemimercaptal derivatives 2a–c, respectively. The stable hemimercaptals 2a–c were characterized by IR, 1H NMR, 13C NMR, MS and elemental analysis. The ester of 2a with 3-(3,5-di-tert-butyl-4-hydroxy-phenyl)propanoic acid (3a) was prepared using triphenylphosphine and diethyl azodicarboxylate (Mitsunobu conditions).

MECHANISM OF THE REACTION OF SOME STABLE HEMIMERCAPTALS WITH Secondary-AMINES: EVIDENCE AGAINST THE INTERMEDIACY OF A METHYLENESULFONIUM ION

Abstract The reaction of the arenethiols 4a-b with formaldehyde and the sec-amines 5a-c gave the aminomethyl aryl sulfides 6a-d. The reaction of the hemimercaptals 3a-b with 5a in methanol gave 6a-b in high yield. In acetonitrile reaction media, 6b was obtained by the reaction of 3b with 5a which suggested that 7b was not an intermediate in the formation of 6b in methanolic media. The absence of 7b in methanolic media suggests that the methylenesulfonium ion 8b is not an reaction intermediate. The formation of 7b was observed in the reaction of 3b with methanol when catalyzed by the Lewis acid tetrafluoroboric acid diethyl ether complex. The experimental observations are best explained by a mechanism whereby 3a-b are in rapid equilibrium with 4a-b under the basic reaction conditions. Rapid reaction of the liberated formaldehyde with 5a leads to the normal Mannich reaction pathway. Consistent with this mechanism, the reaction of a mixture of 3a-b and 12 with 5a gave both 6a-b and 13.

Sterically hindered 4-hydroxybenzenesulfenyl chloride: reactivity with trivalent phosphorus esters

Abstract The reaction of 3,5-di-tert-butyl-4-hydroxybenzenesulfenyl chloride, 1, with the trialkyl phosphites 5a–d gave the corresponding S-(3,5-di-tert-butyl-4-hydroxyphenyl)-O,O-dialkyl phosphorothiolates 6a–d. The formation of 6a–d constitutes chemical evidence for the intermediacy of 1 which was previously inferred from spectroscopic evidence.