Reaction of tricoordinate phosphorus compounds with organophosphorus pseudohalogens. 1. Desulfurization and deoxygenation of oxophosphoranesulfenyl chlorides. Scope and mechanism
摘要:
The reaction of oxophosphoranesulfenyl chlorides RR'P(O)SCl 2 with P(III) compounds has been investigated. Its mechanistic features have been elucidated by variable-temperature P-31 NMR spectroscopy and stereochemical changes at P(IV) and P(III) phosphorus centers. These studies show that in all cases phosphonium intermediates containing the sulfur bridge >P(O)-S-P+ less than or similar to Cl- are formed. Depending on electronic and steric factors and reaction conditions, this primary phosphonium salt either decomposes by nucleophilic attack of the chloride counterion on the phosphoryl center (desulfurization pathway) or is transformed into the isomeric phosphonium salt >P(S)-O-P+ less than or similar to Cl-. The latter decomposes by the attack of the chloride anion on the thiophosphoryl center (deoxygenation pathway). P-31 NMR studies fully corroborated the observed stereochemical changes.
The stereochemistry of 2-alkoxy-4-methyl-1,3,2-dioxaphosphorinans
作者:C. L. Bodkin、P. Simpson
DOI:10.1039/j29710001136
日期:——
The stereochemistry of a series of 2-alkoxy-4-methyl-1,3,2-dioxaphosphorinans has been investigated by n.m.r. and dipole-moment studies. For a given alkoxy-group (MeO, EtO, or PriO), the more-stable member of the isomeric pair adopts a chair conformation, having the trans-configuration, with equatorial methyl and axial alkoxy-group. The less-stable isomers, having the cis-configuration, adopt rapidly
Stereochemistry of organophosphorus cyclic compounds—I
作者:M. Mikołajczyk、J. Łuczak
DOI:10.1016/s0040-4020(01)93865-7
日期:1972.1
Geometrical isomers of 2-hydroxy-2-thio-4-methyl-1,3,2-dioxaphosphorinan (I) and 2- hydroxy-2-seleno-4-methyl-1,3,2-dioxaphosphorinan (V) have been prepared stereospecifically by : (a) demethylation of cis- and trans-2-methoxy-2-thio-4-methyl-1,3,2-dioxaphosphorinan (IV) and 2-methoxy- 2-seleno-4-methyl-1,3,2-dioxaphosphorinan (VI) with trimethylamine, and (b) addition of sulphur and selenium to geometrical
Stereochemistry of organophosphorus cyclic compounds—III
作者:W. Stec、A. Łopusiński
DOI:10.1016/0040-4020(73)80007-9
日期:1973.1
On the basis of chemical transformations and spectroscopic data the cis- and trans-geometry was assigned to the previously reported diastereoisomeric 2-N-phenylamino-2-oxo-4-methyl-1,3,2-dioxaphosphorinans (1). The addition of phenyl azide to cyclic phosphite (3) as well as the reaction of the resulting adduct (4) with carbon disulphide or benzoic acid takes place with overall retention of configuration