QUASIPHOSPHONIUM INTERMEDIATES .7. THE PREPARATION OF TRINORBORN-1-YLPHOSPHITE AND ITS REACTIONS WITH HALOGENO COMPOUNDS - STABLE INTERMEDIATES OF THE ARBUZOV AND PERKOW REACTIONS AND THEIR STRUCTURAL CHARACTERIZATION BY X-RAY-DIFFRACTION, NMR-SPECTROSCOPY, AND FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY
Hr. Hudson et al., QUASIPHOSPHONIUM INTERMEDIATES .7. THE PREPARATION OF TRINORBORN-1-YLPHOSPHITE AND ITS REACTIONS WITH HALOGENO COMPOUNDS - STABLE INTERMEDIATES OF THE ARBUZOV AND PERKOW REACTIONS AND THEIR STRUCTURAL CHARACTERIZATION BY X-RAY-DIFFRACTION, NMR-SPECTROSCOPY, AND FAST-ATOM-BOMBARDMENT MASS-SPECTROMETRY, Perkin transactions. 2, (8), 1993, pp. 1433-1440
Trinorborn-1-yl phosphite has been prepared and has been shown to give
highly stable phosphonium salts in its reactions with iodomethane and
with a number of alpha-halogenoketones. Phenacyl bromide and p-bromop
henacyl bromide underwent reaction at room temperature to give the cor
responding ketophosphonium halides (Arbuzov intermediates) as the excl
usive products, whilst p-nitrophenacyl chloride gave the corresponding
vinyloxyphosphonium chloride (Perkow intermediate) as the first examp
le of a stable intermediate of this type. The structures of these two
types of intermediate in the solid state were confirmed by X-ray diffr
action measurements which revealed distorted tetrahedral arrangements
around phosphorus, with P+ ... Br- and P+ ... Cl- interionic distances
of 4.58 and 4.71 angstrom for the phenacyl bromide and p-nitrophenacy
l chloride adducts respectively. Phenacyl chloride, chloroacetone, and
p-nitrophenacyl bromide gave mixed products, amongst which trinorborn
-1-yl phosphate was always present. Possible reaction mechanisms are d
iscussed. Thermal decomposition of the Arbuzov intermediates (149-degr
ees-C) gave the expected phosphonates but the Perkow intermediate unde
rwent elimination of alkyne under these conditions to give trinorborn-
1-yl phosphate. P-31 NMR and fast atom bombardment mass spectra of the
quasiphosphonium salts are reported and discussed.