Regio- and stereoselective hydrostannation of allenes using dibutyliodotin hydride (Bu2SnIH) and successive coupling with aromatic halides
作者:Naoki Hayashi、Kazunao Kusano、Shingo Sekizawa、Ikuya Shibata、Makoto Yasuda、Akio Baba
DOI:10.1039/b712998j
日期:——
Regio- and stereoselective hydrostannation of allenes by using di-n-butyliodotin hydride (Bu2SnIH) was accomplished to give α,β-disubstituted vinyltins, which induced the synthesis of multi-substituted alkenes in a one-pot procedure.
Saegusa Oxidation of Enol Ethers at Extremely Low Pd-Catalyst Loadings under Ligand-free and Aqueous Conditions: Insight into the Pd(II)/Cu(II)-Catalyst System
作者:Quan Zhu、Yunsong Luo、Yongyan Guo、Yushun Zhang、Yunhai Tao
DOI:10.1021/acs.joc.0c02987
日期:2021.4.16
system of Saegusa oxidation, which converts enolethers to the corresponding enals with a number of diverse substrates at extremely low catalyst loadings (500 mol ppm) under ligand-free and aqueous conditions, is described. Its synthetic utility was demonstrated by large-scale applications of the catalyst system to important nature molecules. This work allows Saegusa oxidation to become a highly practical
Radical Isomerization and Cycloisomerization Initiated by H• Transfer
作者:Gang Li、Jonathan L. Kuo、Arthur Han、Janine M. Abuyuan、Lily C. Young、Jack R. Norton、Joshua H. Palmer
DOI:10.1021/jacs.6b03509
日期:2016.6.22
concentration of an H• donor. Transfer of the H• onto an olefin gives a radical that can either (1) transfer an H• back to the metal, generating an isomerized olefin, or (2) add intramolecularly to a double bond, generating a cyclized radical. Transfer of an H• back to the metal from the cyclized radical results in a cycloisomerization. Both outcomes are favored by the low concentration of the cobalt H• donor,
Photocatalytic Dehydrogenative Cross-Coupling of Alkenes with Alcohols or Azoles without External Oxidant
作者:Hong Yi、Linbin Niu、Chunlan Song、Yiying Li、Bowen Dou、Atul K. Singh、Aiwen Lei
DOI:10.1002/anie.201609274
日期:2017.1.19
Direct cross‐coupling between alkenes/R‐H or alkenes/RXH is a dream reaction, especially without external oxidants. Inputting energy by photocatalysis and employing a cobalt catalyst as a two‐electron acceptor, a direct C−H/X−H cross‐coupling with H2 evolution has been achieved for C−O and C−N bond formation. A new radical alkenylation using alkene as the redox compound is presented. A wide range of
Thermal and Photochemical Solvolysis of (<i>E</i>)- and (<i>Z</i>)-2-Phenyl-1-propenyl(phenyl)iodonium Tetrafluoroborate: Benzenium and Primary Vinylic Cation Intermediates
in-plane S(N)2 mechanism. The mechanism of the photolysis involves direct, unassisted cleavage of the vinylic, and aromatic, C-I bond in an S(N)1 mechanism. This produces a primary vinyl cation, which is partially trapped prior to rearrangement in methanol. The unrearranged vinyl ethers are mainly formed with retention of configuration via a lambda3-iodonium/solvent complex in an S(N)i mechanism. Thermal
已在不同亲核性的醇溶剂中研究了两种立体异构体 2-苯基-1-丙烯基(苯基)碘鎓四氟硼酸盐的热和光化学溶剂分解。热反应中的产物分布和产物形成速率都与涉及在反式位(甲基或苯基)中的基团辅助的乙烯基Cl键断裂的机制相容,总是导致重排产物。根据溶剂的亲核性,最初形成的阳离子可能会或可能不会进一步重排为更稳定的异构体。反应性较低的 Z 化合物还在亲核性更强的溶剂中通过面内 S(N)2 机制产生一些未重排的乙烯基醚产物。光解的机制涉及乙烯基和芳烃的直接、无辅助的裂解,S(N)1 机制中的 CI 键。这会产生一个主要的乙烯基阳离子,它在甲醇中重排之前被部分捕获。未重排的乙烯基醚主要通过 S(N)i 机制中的 lambda3-碘鎓/溶剂络合物保留构型形成。碘鎓盐的热和光化学溶剂分解是从同一底物生成不同阳离子中间体的互补技术。