53198-60-0Relevant academic research and scientific papers
A novel and highly efficient synthetic route to unsymmetrical organoselenides using cesium bases
Cohen, Richard J.,Fox, Daniel L.,Salvatore, Ralph Nicholas
, p. 4265 - 4268 (2007/10/03)
A new and convenient one-pot method for the preparation of unsymmetrical selenides has been developed. In the presence of cesium hydroxide, molecular sieves, and DMF, benzeneselenol undergoes direct alkylation with various alkyl halides for the synthesis of alkyl phenyl selenides in moderate to excellent yields. Another method to prepare unsymmetrical organoselenides was also completed by coupling terminal alkynes with benzeneselenyl bromide. As an application, the synthesis of a selenopeptide was also accomplished. Furthermore, this methodology was extended to the synthesis of an organoselenide on solid support.
Rate Constants for Chalcogen Group Transfers in Bimolecular Substitution Reactions with Primary Alkyl Radicals
Curran, Dennis P.,Martin-Esker, Amanda A.,Ko, Sung-Bo,Newcomb, Martin
, p. 4691 - 4695 (2007/10/02)
Rate constants for group transfers of the MeS, PhS, PhSe, and PhTe groups from chalcogen-substituted acetate, acetonitrile, malonate, and malononitrile compounds, from N-(phenylthio)phthalimide and from Me2S2 and Ph2S2 to primary alkyl radicals, have been determined by competition kinetics using PTOC esters as the radical precursors and competing trapping agents.Thio group transfers from malononitrile derivatives are marginally faster than the corresponding group transfer from the symmetrical disulfide, and the rate constant for PhSe group transfer from PhSeSePh isgreater than those from the derivatives studied here.Substituent effects suggest that the chalcogen transfer reactions may be concerted.For three cases in which direct comparisons can be made, the rate constants for reactions of phenylchalcogenides are approximately equal to those for halogen atom transfer when the chalcogen and halide are in the same row of the periodic table and the radical resulting from displacement is the same.The rate constants reported in this work will be useful for the rational design of synthetic schemes based on homolytic group transfer chemistry.
SYNTHESIS OF α-SELENOALKYLLITHIUM COMPOUNDS
Krief, A.,Dumont, W.,Clarembeau, M.,Bernard, G.,Badaoui, E.
, p. 2005 - 2022 (2007/10/02)
α-Phenylselenoalkyllithiums and α-methylselenoalkyllithiums have been prepared from the corresponding selenoacetals and alkyllithiums.Several features of this reaction are disclosed.For example, the reaction is more readily achieved on phenylselenoacetals than on methylseleno analogues.Those derived from hindered carbonyl compounds are less readily cleaved. s-BuLi/THF proved superior to n-BuLi in THF, itself better than n-BuLi in ether.
SH2 Reactions of Diphenyl Diselenide; Preparation and Reactions of Bridgehead Selenides
Perkins, M. John,Turner, Eric S.
, p. 139 - 140 (2007/10/02)
For the SH2 process R* + PhSeSePh -> PhSeR + PhSe*, k = ca. 5 * 107 l mol-1 s-1 at 80 deg C in benzene when R is primary alkyl; with 1-adamantyl radicals this SH2 displacement affords a route to 1-adamantyl phenyl selenide which, on oxidation and pyrolysis of the resultant selenoxide, gives adamantan-1-ol; in contrast the selenoxide from bicyclononan-1-yl phenyl selenide decomposes via bicyclonon-1-ene.
