594815-53-9Relevant academic research and scientific papers
Copper-Catalyzed Alkylation of Silyl Enol Ethers with Sterically Hindered α-Bromocarbonyls: Access to the Histamine H3Receptor Antagonist
Li, Dengke
, p. 609 - 618 (2020/12/23)
A general and efficient copper-catalyzed alkylation of silyl enol ethers with functionalized alkyl bromides has been developed for the synthesis of the sterically hindered γ-ketoesters. The transformation was induced through C(sp3)-halogen activation of commercially available sterically hindered alkyl bromides under mild conditions in good results. The strategy could be used for the synthesis of biologically active histamine H3 receptor (H3R) antagonist for medicinal purposes.
Organo-photoredox-catalyzed atom-transfer radical substitution of alkenes with α-carbonyl alkyl halides
Nishikata, Takashi,Hirata, Goki,Shimada, Taisei
supporting information, p. 8952 - 8956 (2020/12/02)
A light-driven atom-transfer radical substitution (ATRS) and carboesterification reaction of alkenes with alkyl halides has been developed using PTH as the organo-photoredox catalyst. Two types of products were obtained, depending on the additive and solvent used during the reaction. Primary, secondary, and tertiary alkyl halides reacted to give the ATRS products. This protocol has several advantages: it requires mild reaction conditions and a low catalyst loading and exhibits a broad substrate scope and good functional group tolerance. Mechanistic studies indicate that alkyl radicals might be generated as the key intermediates via photocatalysis, providing a new direction for ATRS reactions.
Palladium-catalyzed cross-coupling of enamides with sterically hindered α-bromocarbonyls
Ding, Ran,Huang, Zhi-Dao,Liu, Zheng-Li,Wang, Tian-Xiang,Xu, Yun-He,Loh, Teck-Peng
, p. 5617 - 5620 (2016/05/09)
Palladium-catalyzed intermolecular alkylation of enamides with α-bromo carbonyls was developed. Under mild reaction conditions, various cyclic and acyclic enamides reacted well with α-bromo carbonyls to afford the corresponding multi-substituted alkene pr
Nickel-Catalyzed Addition-Type Alkenylation of Unactivated, Aliphatic C-H Bonds with Alkynes: A Concise Route to Polysubstituted γ-Butyrolactones
Li, Mingliang,Yang, Yudong,Zhou, Danni,Wan, Danyang,You, Jingsong
supporting information, p. 2546 - 2549 (2015/05/27)
(Chemical Equation Presented). Through the nickel-catalyzed chelation-assisted C-H bond activation strategy, the addition-type alkenylation of unreactive β-C(sp3)-H bonds of aliphatic amides with internal alkynes is developed for the first time to produce γ,δ-unsaturated carboxylic amide derivatives. The resulting alkenylated products can further be transformed into polysubstituted γ-butyrolactones with pyridinium chlorochromate (PCC).
Visible light-induced intermolecular radical addition: Facile access to γ-ketoesters from alkyl-bromocarboxylates and enamines
Hu, Bei,Chen, Haixia,Liu, Yan,Dong, Wuheng,Ren, Kai,Xie, Xiaomin,Xu, Hao,Zhang, Zhaoguo
, p. 13547 - 13550 (2015/01/09)
A highly efficient addition of alkyl α-bromocarboxylates to enamines by visible light-induced photoredox catalysis is reported. Compared with traditional methods, the reaction described here provided an alternative route for the construction of valuable γ-ketoesters in generally good yields.
Carbon-carbon bond formation by radical addition-fragmentation reactions of O-alkylated enols
Cai, Yudong,Roberts, Brian P.,Tocher, Derek A.,Barnett, Sarah A.
, p. 2517 - 2529 (2007/10/03)
α-tert-Butoxystyrene [H2C = C(OBut)Ph] reacts with α-bromocarbonyl or α-bromosulfonyl compounds [R 1R2C(Br)EWG; EWG = -C(O)X or -S(O2)X] to bring about replacement of the bromine atom by the phenacyl group and give R 1R2C(EWG)CH2C(O)Ph. These reactions take place in refluxing benzene or cyclohexane with dilauroyl peroxide or azobis(isobutyronitrile) as initiator and proceed by a radical-chain mechanism that involves addition of the relatively electrophilic radical R 1R2(EWG)C* to the styrene. This is followed by β-scission of the derived α-tert-butoxybenzylic adduct radical to give But*, which then abstracts bromine from the organic halide to complete the chain. α-1-Adamantoxystyrene reacts similarly with R 1R2C(Br)EWG, at higher temperature in refluxing octane using dα-tert-amyl peroxide as initiator, and gives phenacylation products in generally higher yields than are obtained using α-tert-butoxystyrene. Simple iodoalkanes, which afford relatively nucleophilic alkyl radicals, can also be successfully phenacylated using α-1-adamantoxystyrene. O-Alkyl O-(tert-butyldimethylsilyl) ketene acetals H2C=C(OR)OTBS, in which R is a secondary or tertiary alkyl group, react in an analogous fashion with organic halides of the type R1R2C(Br)EWG to give the carboxymethylation products R1R2C(EWG)CH 2CO2Me, after conversion of the first-formed silyl ester to the corresponding methyl ester. The silyl ketene acetals also undergo radical-chain reactions with electron-poor alkenes to bring about alkylation-carboxymethylation of the latter. For example, phenyl vinyl sulfone reacts with H2C=C(OBut)OTBS to afford Bu tCH2CH(SO2Ph)CH2CO2Me via an initial silyl ester. In a more complex chain reaction, involving rapid ring opening of the cyclopropyldimethylcarbinyl radical, the ketene acetal H 2C=C(OCMe2C3H5-cyclo)OTBS reacts with two molecules of N-methyl- or N-phenyl-maleimide to bring about [3 + 2] annulation of one molecule of the maleimide, and then to link the bicyclic moiety thus formed to the second molecule of the maleimide via an alkylation-carboxymethylation reaction.
Carbon-carbon bond formation by radical addition-fragmentation reactions of O-tert-alkyl enols and O-cyclopropylcarbinyl enols
Cai, Yudong,Roberts, Brian P.
, p. 4645 - 4648 (2007/10/03)
Terminal alkenes of the type H2C=C(OR1)X, in which R1 is a tertiary alkyl or a 1-cyclopropylethyl group and X=Ph, OSiMe2But, OEt or H, undergo radical-chain reactions with organic halides R2Hal to give carbonyl compounds R2CH2C(=O)X.
