244240-68-4Relevant academic research and scientific papers
Heck Reaction of Electronically Diverse Tertiary Alkyl Halides
Kurandina, Daria,Rivas, Mónica,Radzhabov, Maxim,Gevorgyan, Vladimir
supporting information, p. 357 - 360 (2018/01/27)
The efficient Pd-catalyzed Heck reaction of diverse tertiary alkyl halides with alkenes has been developed. Unactivated tertiary alkyl halides efficiently react at room temperature under visible light irradiation with no exogenous photosensitizers required. For activated tertiary alkyl halides, the same catalytic system works well without light. These methods offer a general access to electronically diverse alkenes possessing quaternary and functionalized tertiary allylic carbon centers. The substituents at these centers include alkyl-, carbalkoxy-, tosyl-, phosphonyl-, and boronate groups. It was also shown that the end-game mechanism of this transformation may vary depending on the type of the substrates used.
Cu/Ag-catalyzed double decarboxylative cross-coupling reaction between cinnamic acids and aliphatic acids in aqueous solution
Mai, Wen-Peng,Song, Ge,Sun, Gang-Chun,Yang, Liang-Ru,Yuan, Jin-Wei,Xiao, Yong-Mei,Mao, Pu,Qu, Ling-Bo
, p. 19264 - 19267 (2013/10/22)
A novel double decarboxylative cross-coupling catalyzed by copper and silver has been developed. This method provides a practical approach for the flexible synthesis of alkenes and alkynes from the readily affordable substrates.
Detection and reaction of oxaphosphetanes derived from benzaldehyde and 1-adamantylmethylidene ylide
Yamataka, Hiroshi,Takatsuka, Tsutomu,Hanafusa, Terukiyo
, p. 722 - 726 (2007/10/03)
The Wittig reaction of (1-adamantylmethylidene)triphenylphosphorane (PH3P=CH(1-Ad)) with benzaldehyde was investigated, and the results were compared with those of other ylides. The substituent effect in the reaction of the ylide with benzaldehydes was determined by competition experiments, which gave a Hammett p value of 3.2. The p value is much larger than those reported for analogous reactions of Ph3P=CH(CH2)2CH3 (p=0.20) and Ph3P=CH(CH3)2 (p = 0.59), indicating that the reaction mechanism differs for Ph3P=CH(1-Ad) and the other ylides. The cis/trans ratio of the product alkene is 74/26 for the reaction with the parent benzaldehyde and highly depends on the position of the substituent; ortho substituted benzaldehydes gave the trans alkenes up to 90%. Monitoring the reaction by means of 31P NMR revealed that both cis and trans oxaphosphetane intermediates were formed and that the formation and decomposition of the cis oxaphosphetane are 7-12 times faster than those of the trans oxaphosphetane. From the comparison of the reaction of Ph3P=CH(1-Ad) + benzaldehyde with those of Ph3P=CH(CH2)2CH3 + benzaldehyde and benzophenone, and Ph3P=CH(CH3)2 + benzophenone, it was concluded that all the reactions with these nonstabilized ylides proceed via an electron-transfer mechanism and that the rate-determining step changes from the electron transfer step to that of radical combination when the substrate or ylide becomes more sterically demanding.
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.
Synthesis of Adamantane Derivatives. 49. Substitution Reaction of 1-Adamantyl Chloride with Some Trimethylsilylated Unsaturated Compounds
Sasaki, Tadashi,Usuki, Arimitsu,Ohno, Masatomi
, p. 3559 - 3564 (2007/10/02)
Catalytic substitution reactions at the adamantane bridgehead were studied by using α,β- and β,γ-unsaturated trimethylsilanes.Treatment of 1-adamantyl (Ad) chloride (1) with allyltrimethylsilane and its heteroanalogues, X=Y-Z-SiMe3, in the presence of Lewis acid as a catalyst gave the products Ad-X-Y=Z, X=Y+(Ad)-Z-, and X=Y-Z-Ad, depending on the attack site of the adamantyl group on each X, Y, and Z atom.Treatment of 1 with (phenylethynyl)trimethylsilane also gave a substituted adamantane in good yield.The substitution reactions of 1 with aryl- and heteroaryltrimethylsilanes under similar conditions occurred at a position distinct from that of acetylation, indicating that adamantylation was not influenced by an electronic effect of the trimethylsilyl group.
