Phosphaalkene-vinylphosphine rearrangement of organoboron acylphosphine derivatives

Journal Article · Tue Sep 01 04:00:00 EDT 1987 · Dokl. Chem. (Engl. Transl.); (United States)

OSTI ID:5796655

Veits, Yu A; Neganova, E G; Borisenko, A A; Brusov, R V; Foss, V L; Lutsenko, I F

Organoboron derivatives of acyl-tert-butylphosphines t-BuP=C(OBR/sub 2//sup 1/)R/sup 2/ (I) obtained in their recent work contain a dicoordinated phosphorus atom. /sup 13/C-NMR spectra in the case in which R/sup 2/ = t-Bu and R/sup 1/ = Me/sub 2/N (Ia) or Bu (Ib) show that these compounds are Z isomers, i.e., have the same structure as the silyl derivatives of pivaloyl-tert-butylphosphine. However, a decrease in the steric strain in the acylphosphine leads to the almost quantitative formation of the E isomer in the synthesis of organoboron derivatives of tert-butylisobutyrylphosphine (R/sup 2/) = i-Pr) under kinetic control conditions and equilibrium with predominance of the Z isomer being established only subsequently. In the case of bulkier substituents at the boron atom, the equilibrium fraction of the E isomer is somewhat higher: 10% for Ic (R/sup 1/ = Me/sub 2/N, R/sup 2/ = i-Pr) and 15% for Id (R/sup 1/ = Et/sub 2/N, R/sup 2/ = i-Pr). The fraction of the E isomer increases markedly upon heating Ic and Id and the systems return to their original state upon cooling. The E-Z isomerization is significantly accelerated by boron halides. Thus, virtually pure E isomer of Id in the presence of 10% (Et/sub 2/N)/sub 2/BCl is converted at 20/sup 0/C over 24 h to almost the equilibrium isomer mixture, while without catalyst, the content of the E isomer drops by only 25%. The finding of electrophilic catalysis, in their opinion, indicated the intermediate formation of compounds with a P-B bond which are isomeric to I.

• Research Organization: M. V. Lomonosov Moscow State Univ., USSR
• OSTI ID: 5796655
• Journal Information: Dokl. Chem. (Engl. Transl.); (United States), Journal Name: Dokl. Chem. (Engl. Transl.); (United States) Vol. 292:4-6; ISSN DKCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
640302 -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
BORON COMPLEXES
CARBON 13
CARBON ISOTOPES
CATALYTIC EFFECTS
CHEMICAL REACTIONS
CHEMICAL SHIFT
COMPLEXES
COMPLEXOMETRY
COUPLING
COUPLING CONSTANTS
EVEN-ODD NUCLEI
HYDRIDES
HYDROGEN 1
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
HYDROGEN TRANSFER
INTERMEDIATE COUPLING
ISOMERIZATION
ISOMERS
ISOTOPES
J-J COUPLING
LIGHT NUCLEI
NMR SPECTRA
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
ORGANOMETALLIC COMPOUNDS
PHOSPHINES
PHOSPHORUS 31
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
SILANES
SILICON COMPOUNDS
SPECTRA
STABLE ISOTOPES
STRUCTURAL CHEMICAL ANALYSIS