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.
Synthesis and Conformational Analysis of Six-Membered Cyclic Phenyl Phosphites
摘要:
A procedure for synthesizing potentially anancomeric equatorial phenyl phosphites (cis-l and eq-cis-2) is reported. Spectral characteristics and low-temperature NMR studies on the phenyl phosphites suggest that eq-cis-a is a system with a predominant chair conformation in solution. On the contrary, cis-l is conformationally heterogeneous.
Borisov, E. V.; Akhlebinin, A. K.; Nifant'ev, E. E., Journal of general chemistry of the USSR, 1984, vol. 54, # 10, p. 2096 - 2100
作者:Borisov, E. V.、Akhlebinin, A. K.、Nifant'ev, E. E.
DOI:——
日期:——
Reaction of tricoordinate phosphorus compounds with organophosphorus pseudohalogens. 1. Desulfurization and deoxygenation of oxophosphoranesulfenyl chlorides. Scope and mechanism
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.
Synthesis and Conformational Analysis of Six-Membered Cyclic Phenyl Phosphites
A procedure for synthesizing potentially anancomeric equatorial phenyl phosphites (cis-l and eq-cis-2) is reported. Spectral characteristics and low-temperature NMR studies on the phenyl phosphites suggest that eq-cis-a is a system with a predominant chair conformation in solution. On the contrary, cis-l is conformationally heterogeneous.