866-23-9Relevant articles and documents
DIREKTSYNTHESE VON N,N-DIORGANYL-PHOSPHORSAEUREDIALKYLESTERAMIDEN AUS TRIALKYLPHOSPHITEN
Albrecht, Steffen,Herrmann, Eckhard
, p. 189 - 192 (2007/10/02)
Dialkyl N,N-Diorganylphosphoroamidates result in the reaction of trialkylphosphites with secondary amines and tetrachlormethane if amine hydrochlorides are used as catalysts.A reaction mechanism is proposed.Key words: N,N-Diorganylphosphoroamidates; trialkylphosphites; tetrachlormethane.
REACTIVITY OF TRIETHYL PHOSPHITE WITH TETRACHLOROMETHANE : ELECTRON TRANSFER VERSUS IONIC SUBSTITUTION ON "POSITIVE" HALOGEN
Bakkas, Salem,Julliard, Michel,Chanon, Michel
, p. 501 - 512 (2007/10/02)
The reaction of triethyl phosphite (1) with tetrachloromethane (2) has been studied from a mechanistic point of view. 1 reacts at 80 deg C with 2 to form diethyltrichloromethanephosphonate (3) (85-90percent yield) and chloroethane (4) (80percent yield).Several results hint at a radical chain mechanism (like SRN1).Trichloromethyl radical is trapped by 2,6-di-t-butyl-4-cresol (BHT), the reaction may be initiated with UV radiation (254 nm) and a charge transfer complex (CTC) is formed between 1 and 2 ; furthermore, the reaction is inhibited by 7,7',8,8' tetracyanoquinodimethane (TCNQ).Tris(cyclopropylmethyl)phosphite (12a) and tri(1-hexene-6-yl) phosphite (7a) are used as potential radical clocks in these reactions.The first leads inter alia to 3-chloro-1-butene (17) and the second to 5-chloro-1-hexene (11), the first therefore suggests a radical mechanism but not the second.However in this particular case even the results obtained with the tris(cyclopropylmethyl)phosphite may be rationalized also by an ionic mechanism.For the photostimulated reaction , the overall quantum yield is 0.1.The electrochemical oxidation of 1 with added CCl4 does not account for a radical chain process as the main pathway.Furthermore, the application of Marcus analysis to reaction viewed as an electron transfer leads to a calculated rate constant in the range of 10-20 M-1s-1.The synergy of the techniques that we used lead us to conclude that the thermal reaction is in fact an SNCl+ substitution.The radical intermediates would mainly be derived from the electron-transfer reaction between CCl3- and CCl4 the importance of which increases when special conditions such as hν activation are applied.Reaction therefore provides an example where the observed paramagnetic species during a D/A interaction could deceptively suggest an electron-transfer between D and A whereas they originate from an interaction between A and an electron donor formed after or during the first step of the reaction.
INTERACTION OF DIALKYL TRIMETHYLSILYL PHOSPHITES WITH CARBON TETRACHLORIDE
Gazizov, T. Kh.,Ustanova, L. N.,Ryzhikov, D. V.,Pudovik, A. N.
, p. 1673 - 1674 (2007/10/02)
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