88458-84-8Relevant academic research and scientific papers
Synthesis of Adamantane Derivatives by Bridgehead Radical Addition to Electron-Deficient Unsaturated Bonds
Ohno, Masatomi,Ishizaki, Kenichi,Eguchi, Shoji
, p. 1285 - 1288 (2007/10/02)
Introduction of β-functional alkyl and alkenyl groups to the adamantane bridgehead was carried out by radical-mediated reactions of 1-adamantyl bromide and iodide (1a and 1b) with alkenes and alkynes containing electron-withdrawing groups in the presence of tributyltin hydride and AIBN.As expected, the reactions of polybromoadamantanes 7-9 with acrylonitrile gave 1,3-, 1,3,5-, and 1,3,5,7-polycyanoethyl-substituted derivatives; yield decreased with increasing substitution.Notably, by this method, α-hydroxy ester and monohydrazine derivatives were obtained by using the silyl enol ether of pyruvate ester and diethyl azodicarboxylate as a radical acceptor, respectively.The course of reaction is rationalized as a radical chain cycle, and the reactivity pattern of alkenes indicates that the radical addition process is governed by a SOMO-LUMO interaction of a radical and an alkene.A recently reported reaction of an alkyl halide with a zinc-copper couple in aqueous ethanol is complementary to the above tin method.Thus, 1b reacted with α,β-unsaturated carbonyl compounds in the presence of a zinc-copper couple; in some cases the yield was improved greatly.
Cross-Coupling Reaction of tert-Alkyl halides with Grignard Reagents in Dichloromethane as a Non-Lewis Basic Medium
Ohno, Masatomi,Shimizu, Kazuo,Ishizaki, Kenichi,Sasaki, Tadashi,Eguchi, Shoji
, p. 729 - 733 (2007/10/02)
In dichloromethane as a non-Lewis basic solvent, 1-haloadamantane 1 underwent a cross-coupling reaction with Grignard reagents to give bridgehead-substituted products 3-16 in moderate yields.In this case the same kind of halogen in both 1 and a Grignard reagent was favored; if not, functional exchange (i.e., 1a to 1c) occurred first.The reaction using 5-hexenylmagnesium bromide as a radical probe afforded uncyclized/cyclized coupling products in a 6/4 ratio.These fact suggested the significant participation of the single-electron-transfer process in these reactions.The present method could be extended to tert-butylation with some Grignard reagents.Interestingly, 1,3-dichloro-3-methylbutane coupled with butylmagnesium chloride selectively at the tertiary position. for the above displacement reaction of 1, an organozinc was also found to be effective.
