54537-87-0Relevant academic research and scientific papers
Mechanistic investigation of the reaction between α-sulfonyl carbanions and polyhalogenomethanes. Electron transfer versus polar pathways
Mattalia,Vacher,Samat,Chanon
, p. 4111 - 4119 (2007/10/02)
A number of α-sulfonyl carbanion precursors, whose structures include a double bond appropriately situated to intramolecularly trap the potential radical formed by 1-e oxidation, have been synthesized and reacted with CCl4, CBr4, and
A SIMPLE SINTHESIS OF TROPONES AND RELATED COMPOUNDS
Barbier, Michael,Barton, Derek H. R.,Devys, Michel,Topgi, Ravindra Satish
, p. 5031 - 5038 (2007/10/02)
Cyclohexa-2,4- and 2,5-dienones bearing position 2 or 4 a dihalomethyl group (halogen = chlorine or bromine) are smoothly reduced by tri-butyltin hydride to furnish appropriately substituted tropones.Modification of the substituents permits access to a tropolone and to less substituted tropones.The mechanism of this ring expansion process has been discussed.
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.
A Simple Synthesis of the Tropone Nucleus
Barbier, Michel,Barton, Derek H. R.,Devys, Michel,Topgi, Ravindra Satish
, p. 743 - 744 (2007/10/02)
Reduction of suitably substituted dichloro- or dibromo-methylcyclohexadienones with tributyltin hydride affords tropones (or tropolones) in medium to excellent yield; ortho- and para-substituted cyclohexadienones afford the same tropone.
