examples of an iron‐catalyzed three‐component synthesis of homoallylic boronates from regioselective union of bis(pinacolato)diboron, an alkenyl halide (bromide, chloride or fluoride), and an olefin are disclosed. Products that bear tertiary or quaternary carbon centers could be generated in up to 87 % yield as single regioisomers with complete retention of the olefin stereochemistry. With cyclopropylidene‐containing
Synthesis of Alkylated Monofluoroalkenes via Fe-Catalyzed Defluorinative Cross-Coupling of Donor Alkenes with <i>gem</i>-Difluoroalkenes
作者:Ling Yang、Wei-Wei Ji、E Lin、Ji-Lin Li、Wen-Xin Fan、Qingjiang Li、Honggen Wang
DOI:10.1021/acs.orglett.8b00471
日期:2018.4.6
A reductive cross-coupling of gem-difluoroalkenes with diverse unactivated and heteroatom substituted olefins through a Fe-catalyzed hydrogen atom transfer (HAT) strategy is reported. Different from the previous HAT-type olefin cross-coupling reactions, the presence of a fluorineatom in the molecule results in a stereoselective β-F cleavage, leading to a C(sp2)–C(sp3) bond formation. A wide variety
Palladium-Catalyzed Suzuki-Miyaura Cross-Coupling of Secondary α-(Trifluoromethyl)benzyl Tosylates
作者:Marta Brambilla、Matthew Tredwell
DOI:10.1002/anie.201706631
日期:2017.9.18
palladium‐catalyzed C(sp3)−C(sp2) Suzuki–Miyaura cross‐coupling of aryl boronic acids and α‐(trifluoromethyl)benzyl tosylates is reported. A readily available, air‐stable palladium catalyst was employed to access a wide range of functionalized 1,1‐diaryl‐2,2,2‐trifluoroethanes. Enantioenriched α‐(trifluoromethyl)benzyl tosylates were found to undergo cross‐coupling to give the corresponding enantioenriched
Stereodivergent hydrodefluorination of gem-difluoroalkenes: selective synthesis of (Z)- and (E)-monofluoroalkenes
作者:Ryoto Kojima、Koji Kubota、Hajime Ito
DOI:10.1039/c7cc05225a
日期:——
We have developed a novel approach for the stereodivergent hydrodefluorination of gem-difluoroalkenes using copper(I) catalysts to obtain stereodefined monofluoroalkenes. Both (Z)- and (E)-terminal monofluoroalkenes were obtained by hydrodefluorination of gem-difluoroalkenes in the presence of copper(I) catalysts and diboron or hydrosilane, respectively, with high stereoselectivity. DFT calculations
A catalytic C(sp2)–F bond carboxylation with CO2 is reported; the reaction is enabled by dual photoredox/palladium catalysis and involves a crucial fluoroalkenyl radical intermediate.