13343-40-3Relevant academic research and scientific papers
Synthesis of gem-Difluorocyclopropanes in a Phase-transfer Catalysed System
Balcerzak, Pawel,Fedorynski, Michal,Jonczyk, Andrzej
, p. 826 - 827 (1991)
Reaction of CH2Br2 with CBr2F2 and alkenes 1a-e in the presence of 60percent aqueous KOH and tetrabutylammonium hydrogensulphate as a catalyst affords gem-difluorocyclopropanes 2a-e.
Carbenoid reactions of organoelemental compounds containing trifluoromethyl groups: VII. Difluorocyclopropanation of olefins and dienes with a system tris(trifluoromethyl)bismuth-aluminum chloride
Kirii,Pazenok,Yagupolskii,Naumann,Turra
, p. 207 - 209 (2001)
Tris(trifluoromethyl)bismuth generates difluorocarbene at -30°C in the presence of aluminum chloride. By reaction of the difluorocarbene with isobutylene, styrene, cyclohexene, and 2,3-dimethyl-butadiene the corresponding substituted difluorocyclopropanes were obtained.
Sodium trifluoroacetate: An efficient difluorocarbene precursor for alkenes
Chang, Ying,Cai, Chun
, p. 1440 - 1441 (2005)
A novel and efficient difluorocarbene precursor was achieved. In a convenient procedure, a variety of alkenes could be gem-difluorocyclopropanated with sodium trifluoroacetate to give the corresponding products in moderate to high yields, using azobisisob
Palladium-catalyzed allylic alkylation dearomatization of β-naphthols and indoles withgem-difluorinated cyclopropanes
Fu, Zhiyuan,Zhu, Jianping,Guo, Songjin,Lin, Aijun
supporting information, p. 1262 - 1265 (2021/02/09)
A palladium-catalyzed allylic alkylation dearomatization of β-naphthols and indoles withgem-difluorinated cyclopropanes has been developed. This reaction provided an efficient route to access 2-fluoroallylic β-naphthalenones and indolenines bearing quaternary carbon centers in good yields with highZ-selectivityviaC-C bond activation, C-F bond cleavage and the dearomatization process, benefiting from the wide substrate scope and good functional group tolerance. Moreover, 2-fluoroallylic furanoindoline and pyrroloindolines were achieved in good efficiencyviacascade allylic alkylation, dearomatization and cyclization processes in the presence of Et3B.
Rhodium Catalyzed Regioselective C?H Allylation of Simple Arenes via C?C Bond Activation of Gem-difluorinated Cyclopropanes
Jiang, Zhong-Tao,Huang, Jiangkun,Zeng, Yaxin,Hu, Fangdong,Xia, Ying
supporting information, p. 10626 - 10631 (2021/04/05)
Herein, we report a rhodium catalyzed directing-group free regioselective C?H allylation of simple arenes. Readily available gem-difluorinated cyclopropanes can be employed as highly reactive allyl surrogates via a sequence of C?C and C?F bond activation, providing allyl arene derivatives in good yields with high regioselectivity under mild conditions. The robust methodology enables facile late-stage functionalization of complex bioactive molecules. The high efficiency of this reaction is also demonstrated by the high turnover number (TON, up to 1700) of the rhodium catalyst on gram-scale experiments. Preliminary success on kinetic resolution of this transformation is achieved, providing a promising access to enantio-enriched gem-difluorinated cyclopropanes.
Palladium-Catalyzed Defluorinative Alkylation of gem-Difluorocyclopropanes: Switching Regioselectivity via Simple Hydrazones
Lv, Leiyang,Li, Chao-Jun
supporting information, p. 13098 - 13104 (2021/05/03)
Conventional approaches for Pd-catalyzed ring-opening cross-couplings of gem-difluorocyclopropanes with nucleophiles predominantly deliver the β-fluoroalkene scaffolds (linear selectivity). Herein, we report a cooperative strategy that can completely switch the reaction selectivity to give the alkylated α-fluoroalkene skeletons (branched selectivity). The unique reactivity of hydrazones that enables analogous inner-sphere 3,3′-reductive elimination driven by denitrogenation, as well as the assistance of steric-embedded N-heterocyclic carbene ligand, are the key to switch the regioselectivity. A wide range of hydrazones derived from naturally abundant aryl and alkyl aldehydes are well applicable, and various gem-difluorocyclopropanes, including modified pharmaceutical and biological molecules, can be efficiently functionalized with high value alkylated α-fluorinated alkene motifs under mild conditions.
Three-component reaction ofgem-difluorinated cyclopropanes with alkenes and B2pin2for the synthesis of monofluoroalkenes
Suliman, Ayman M. Y.,Ahmed, Ebrahim-Alkhalil M. A.,Gong, Tian-Jun,Fu, Yao
supporting information, p. 6400 - 6403 (2021/07/02)
Borylative difunctionalization of alkenes has emerged as a powerful approach for synthesizing highly functionalized molecules. Herein, dual Cu/Pd-catalysed borylfluoroallylation of alkenes was smoothly achieved by usinggem-difluorinated cyclopropanes and
One-step synthesis of 2,3-difluoronaphthalene by the gas-phase co-pyrolysis of styrene with chlorodifluoromethane
Volchkov,Lipkind,Nefedov
, p. 1232 - 1238 (2019/07/15)
The gas-phase co-pyrolysis of styrene with CHClF2 in a flow reactor at 550–650 °C gives 2,3-difluoronaphthalene in two parallel reaction channels. The main channel includes decomposition of CHClF2 to difluorocarbene, whose subsequent
Ring-Opening Functionalization of Simple gem-Difluorocyclopropanes by Single-Electron Oxidants
Goto, Toshihito,Kawasaki-Takasuka, Tomoko,Yamazaki, Takashi
, p. 9509 - 9518 (2019/08/26)
It was reported for the first time that single-electron oxidants such as CAN or K2S2O8 affected facile ring opening of simple gem-difluorocyclopropanes to afford 1,3-dibromo-2,2-difluoropropanes in good yields by the action of KBr, and the appropriate choice of conditions allowed to incorporate not only second halogen atoms but also hydroxy or acetamido groups at the C1 position in the difluoropropane structures in a regiospecific fashion after initiation of the reaction by the introduction of the first bromine atom at the C3 position. ?
Transition Metal-free gem-difluorocyclopropanation of Alkenes with CF3SiMe3?NaI System: a Recipe for Electron-deficient Substrates
Nosik, Pavel S.,Ryabukhin, Sergey V.,Grygorenko, Oleksandr O.,Volochnyuk, Dmitriy M.
, p. 4104 - 4114 (2018/10/02)
Reaction of various electron-deficient alkenes, as well as functionalized styrene derivatives with CF3SiMe3?NaI system is studied. Relative reactivity of the substrates is established. It is shown that many α,β-unsaturated esters can
