Cobalt-catalyzed Heck-type reaction of alkyl halides with styrenes

A cobalt complex, CoCl2[1,6-bis(diphenylphosphino)hexane], catalyzes an alkylation reaction of styrenes in the presence of Me3SiCH2MgCl in ether to yield beta-alkylstyrenes. A variety of alkyl halides including alkyl chlorides can be employed as an alkyl source. A radical mechanism is strongly suggested for this alkylation reaction.     

Copper-catalyzed reaction of alkyl halides with cyclopentadienylmagnesium reagent

Treatment of alkyl halides, including tertiary alkyl bromides, with cyclopentadienylmagnesium bromide in the presence of a catalytic amount of copper(II) triflate yielded the corresponding cyclopentadienylated products in high yields. The following hydrogenation of the products provided alkyl-substituted cyclopentanes.     

Formation of association ions in the photoionization of alkyl halides

The methyl and ethyl chlorides and bromides, as well as methyl iodide, were photoionized in the vacuum ultraviolet at 300 K in a mass spectrometer over the pressure range 0.5 to approximately 100 millitorr. Under these conditions, stabilized parent ion dimers are found in CH₃Br, CH₃I, and C₂H₅Br, but not in the chlorides. Lower limits for the dissociative lifetimes of the ion–molecule collision complexes were estimated and are as follows: (CH₃Br)₂⁺, 1.6 μs; (CH₃I)₂⁺, 1.9 μs; and (C₂H₅Br)₂⁺, 5.4 μs. An increase in photon energy (internal energy content of the reactant ion) decreases the dissociative lifetime of the collision complex in CH₃I.     

Formation of 2h-benzimidazole-l,3-dioxides by reaction of benzofuroxans with alcohols and alkyl halides in the presence of acids

Reaction of benzofuroxan and S-nitrobenzofuroxan with alcohols and alkyl halides in concentrated suoltric or perchloric acid leads to the formation of 2H-benzinddazole-1,3-dioxides.     

Stereospecific cross-coupling between alkenylboronates and alkyl halides catalyzed by iron-bisphosphine complexes

A stereospecific and high-yielding cross-coupling reaction between alkenylboron reagents and alkyl halides is described. The reaction has been achieved by using well-defined iron-bisphosphine complexes such as 1b FeCl(2)(3,5-t-Bu(2)-SciOPP), which was recently developed by the authors' group. Various nonactivated alkyl bromides and chlorides possessing a base/nucleophile-sensitive functional group can participate in the cross-coupling, demonstrating its utility for stereoselective synthesis of functional molecules bearing a carbon-carbon double bond.     

New data on the reaction of trialkyl trithiophosphites with alkyl halides

Conclusions The major pathway for the reaction of trialkyl trithiophosphites with alkyl halides is alkylation of the phosphorus atom with the formation of alkylthionephosphonates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1871–1873, August, 1987.     

Synthesis of enantiomerically pure telluronium salts by the reaction of chiral tellurides with alkyl halides

Enantiomerically pure benzyl and ethoxycarbonylmethyl telluronium salts 4, using 2-exo-hydroxy-10-bornyl group as a chiral ligand, have been prepared in good yield and diastereoselectivity by the reaction of chiral tellurides 3 with alkyl halides. A structure with R_Te absolute configuration at the tellurium atom was confirmed by an X-ray analysis of 4a.     

A new addition reaction of trialkyl phosphite and alkyl halide to nitrone

N-Substituted 1-(alkoxyamino)alkylphosphonates were obtained by a new addition reaction of trialkyl phosphite and alkyl halide to nitrone. A push-pull type mechanism was suggested for the addition reaction.     

有机磷化合物的研究 X:五价膦(磷)酸酯与卤代烷在卤化钠存在下的酯烷基交换反应

A detailed study on the ester alkyl exchange reaction of various types of quinique-valent phosphorus esters with alkyl halide in the presence of sodium bromides was reported. This ester alkyl exchange reaction was evidently influenced by the structure of phosphorus esters and alkyl halides as well as by the nature of the halides of metal ions. In contrast with the reaction without sodium hadlide, the alkyl phosphinmate is more reactive than phosphonate and phosphate by treatment with alkyl halide in the presence of sodium halide. This is consistent with the high nucleophilicity of >P(CO)O- as leaving group. The reactivity of butyl halides was decreased in the following order: n-BuBr>i-BuBr=s-BuBr>t-BuBr. Alkyl iodide was proved to be more reactive than the corresponding bromide and chloride. However, the use of iodioe is limited by the formation of alkene resulted from the elimination of HI. These structural effects show the general characteristics of a nucleophilic substitution reaction. A reaction mechanism involving the formation of sodium salt intermecutiate was proposed based on the concept of HSAB principle. This reaction may, however, be used as a convenient method for the preparation of mixed esters of quinque-valent phosphorus acids.