67145-73-7Relevant academic research and scientific papers
Electrophilic additions to allenes. VII. The role of steric versus electronic effects in the reactions of areneselenenyl halides with allenes
Garratt, Dennis G.,Beaulieu, Pierre L.,Morisset, Veronique M.,Ujjainwalla, Mark
, p. 2745 - 2753 (2007/10/02)
The reactions of benzeneselenenyl chloride, bromide, and 2,4,6-trimethylbenzeneselenenyl bromide with alkyl 1,3-disubstituted allenes in methylene chloride solution have been investigated.While kinetic data are in accord with similar rate determining transition states, exhibiting strong steric effects for all three species, the product distributions show changes in both chemoselectivity and configurational-selectivity in accord with two different types of steric interaction mechanisms during the product determining transition states.A mechanism involving rate limiting formation of alkylideneseleniranium ions and/or alkylideneepiselenuranes, followed by isomerization between the alkylideneseleniranium ions by a path not involving allylic ions, prior to the product determining transition states, is proposed.
Electrophilic additions to allenes. VI. The role of steric versus electronic effects in the reactions of arenesulphenyl halides with allenes
Garratt, Dennis G.,Beaulieu, Pierre L.
, p. 2738 - 2744 (2007/10/02)
The role of steric and electronic effects during the rate and product determining steps for the addition of arenesulphenyl chlorides to 1,3-disubstituted allenes has been briefly examined.Both effects appear to be generally of minimal importance during the rate determinig step.The available rate data indicate the presence of little, if any, build up of positive charge on sulphur.These results are interpreted in terms of an SN2 attack on bivalent sulphur leading to an alkylidenethiiranium ion intermediate.Steric effects are of greater importance in the product determinig step, particularly when the sulphenyl chlorides possess two bulky ortho substituents, as in the case of 2,4,6-triisopropylbenzenesulphenyl chloride.
Electrophilic additions to allenes. IV. Concerning the nature of the ortho-nitro group effect in the reaction of arenesulphenyl chlorides with allenes.
Garratt, Dennis G.,Beaulieu, Pierre L.
, p. 1275 - 1280 (2007/10/02)
The reactions of twelve arenesulphenyl chlorides, five of which contained an ortho-nitro substituent, with ten 1,3-disubstituted allenes, using methylene chloride as solvent, are described.No evidence for a special ortho-nitro group effect involving a spirosulphurane type intermediate is observed.Variations in the chemoselectivity and configurational-selectivity of the additions are interpreted in terms of steric interactions in the product determining transition state.
