103682-35-5Relevant academic research and scientific papers
HYDROCARBON ANALOGUES OF THE TYPE II PHOTOELIMINATIONS OF KETONES. PHOTOCHEMISTRY OF 1-SUBSTITUTED 4-PHENYL-4-PENTENES.
Hornback,Proehl
, p. 7367 - 7373 (1979)
Direct irradiation of 1,4-diphenyl-4-penten-1-ol produces mainly 2-methyl-2,5-diphenyltetrahydrofuran, while benzophenone-sensitized photolysis gives alpha -methylstyrene, acetophenone, and 1,4-diphenyl-1-pentanone. The direct irradiation is postulated to proceed via the radical anion of the alkene. A mechanism for the inefficient triplet state reaction ( PHI equals 0. 0005) is proposed which involves initial hydrogen abstraction by the methylene carbon of the excited alkene to give a 1,4 biradical, which then produces the observed products. The mechanism is analogous to the accepted mechanism for the type II photofragmentation of ketone. The mechanism is supported by solvent effects and deuterium-labeling studies. Two related alkenes, 4-phenyl-4-penten-1-ol and 1,4-diphenyl-4-pentene, show similar photochemical behavior, although they react even less efficiently than 1,4-diphenyl-4-penten-1-ol.
Reductive Alkylation of Alkenyl Acetates with Alkyl Bromides by Nickel Catalysis
Bai, Yunfei,Han, Guan-Yu,He, Rong-De,Liu, Xue-Yuan,Pan, Xiaobo,Pang, Xiaobo,Shu, Xing-Zhong,Zhao, Zhen-Zhen
supporting information, (2021/12/14)
Catalytic alkylation of stable alkenyl C?O electrophiles is synthetically appealing, but studies to date have typically focused on the reactions with alkyl Grignard reagents. We report herein a cross-electrophile reaction of alkenyl acetates with alkyl bromides. This work has enabled a new method for the synthesis of aliphatic alkenes from alkenyl acetates to be established that can be used to add more structural complexity and molecular diversity with enhanced functionality tolerance. The method allows for a gram-scale reaction and modification of biologically active molecules, and it affords access to useful building blocks. Preliminary mechanistic studies reveal that the NiI species plays an essential role for the success of the coupling of these two reactivity-mismatched electrophiles.
Unlocking the Accessibility of Alkyl Radicals from Boronic Acids through Solvent-Assisted Organophotoredox Activation
Ranjan, Prabhat,Pillitteri, Serena,Coppola, Guglielmo,Oliva, Monica,Van der Eycken, Erik V.,Sharma, Upendra K.
, p. 10862 - 10870 (2021/09/08)
Despite their prevalence in organic synthesis, the application of boronic acids (BAs) as alkyl radical precursors in visible-light-assisted photocatalyzed reactions has been limited by their high oxidation potential. This study demonstrates the prominent
Recyclable and reusable PdCl2(PPh3)2/PEG-400/H2O system for the hydrophenylation of alkynes with sodium tetraphenylborate
Liu, Rong,Zhang, Tingli,Huang, Bin,Cai, Mingzhong
, p. 172 - 178 (2020/07/04)
A stable and efficient PdCl2(PPh3)2/PEG-400/H2O catalytic system for the hydrophenylation reaction of alkynes has been developed. In the presence of 3 mol% PdCl2(PPh3)2 and 2 equiv. of HOAc, the hydrophenylation of both terminal and internal alkynes with sodium tetraphenylborate proceeded smoothly in a mixture of PEG-400 and water at room temperature or 50 °C to afford a variety of phenyl-substituted alkenes in moderate to high yields. The isolation of the products was easily performed by extraction with petroleum ether, and the PdCl2(PPh3)2/PEG-400/H2O system could be readily recycled and reused six times without apparent loss of catalytic activity.
Decarboxylative Negishi Coupling of Redox-Active Aliphatic Esters by Cobalt Catalysis
Liu, Xu-Ge,Zhou, Chu-Jun,Lin,Han, Xiang-Lei,Zhang, Shang-Shi,Li, Qingjiang,Wang, Honggen
, p. 13096 - 13100 (2018/09/21)
A cobalt-catalyzed decarboxylative Negishi coupling reaction of redox-active aliphatic esters with organozinc reagents was developed. The method enabled efficient alkyl–aryl, alkyl–alkenyl, and alkyl–alkynyl coupling reactions under mild reaction conditions with no external ligand or additive needed. The success of an in situ activation protocol and the facile synthesis of the drug molecule (±)-preclamol highlight the synthetic potential of this method. Mechanistic studies indicated that a radical mechanism is involved.
Vinyldimethylphenylsilanes as safety catch silanols in fluoride-free palladium-catalyzed cross-coupling reactions
Anderson, James C.,Munday, Rachel H.
, p. 8971 - 8974 (2007/10/03)
A series of five structurally diverse vinyldimethylphenylsilanes have been shown to undergo a fluoride-free one-pot palladium-catalyzed cross-coupling reaction with phenyl iodide to give ipso coupled products in 62-86% yield. The limitations of this present protocol lie in the activation of Si-Ph vs protodesilylation by KOTMS/18-C-6, which seems sensitive to the sterics of cis substituents, but not geminal substituents.
