Palladium-Catalyzed Carbocyclizations of Unactivated Alkyl Bromides with Alkenes Involving Auto-tandem Catalysis
作者:Alexander R. O. Venning、Megan R. Kwiatkowski、Joan E. Roque Peña、Brendan C. Lainhart、Akil A. Guruparan、Erik J. Alexanian
DOI:10.1021/jacs.7b06794
日期:2017.8.23
carbocyclization of unactivated alkyl bromides with alkenes is described. This approach uses a commercially available bisphosphine ligand and avoids the use of carbon monoxide atmosphere present in prior studies involving alkyl iodides. Detailed mechanistic studies of the transformation are performed, which are consistent with auto-tandem catalysis involving atom-transfer radical cyclization followed by catalytic
One-Pot Synthesis of Tetrahydrofuran Derivatives from Allylic Alcohols and Vinyl Ethers by Means of Palladium(II) Acetate
作者:Keigo Fugami、Koichiro Oshima、Kiitiro Utimoto
DOI:10.1246/bcsj.62.2050
日期:1989.6
Reaction of allylicalcohol with vinyl ether in the presence of Pd(OAc)2 afforded furanderivatives in good yield. Pd(OAc)2 was essential for the reaction. PdCl2 complex did not afford cyclized product but gave acetal exclusively. Three components were combined at once to produce 4-(3-butenyl)-2-butoxy-4-methyltetrahydrofuran upon treatment of a mixture of 2-methyl-2-propen-1-ol, butyl vinyl ether
Nickel‐Catalyzed Mizoroki–Heck‐Type Reactions of Unactivated Alkyl Bromides
作者:Megan R. Kwiatkowski、Erik J. Alexanian
DOI:10.1002/anie.201810757
日期:2018.12.17
The development of a general, nickel-catalyzed alkyl-Mizoroki-Heck reaction of unactivated alkylbromides is described. The mild reaction proceeds efficiently using a wide range of primary and secondary alkylbromides, and examples of intermolecular cross-couplings are provided. Reaction alkene regioselectivity is significantly enhanced over prior carbocyclizations using palladium catalysis. Mechanistic
(2) radicalcyclization, and (3) recombination of radical and manganese species giving alkylmanganese(II) compound. The reaction proved to proceed in the presence of a catalytic amount of manganese(II) chloride under atmospheric oxygen. The manganese catalyzed radicalcyclization could also be applied to 2-iodoethanal acetal, in which case the presence of oxygen was not necessary.
用锰酸三丁酯(n-Bu3MnLi 或 n-Bu3MnMgBr)处理烯丙基 2-卤代苯基醚以良好的收率提供二氢苯并呋喃衍生物。从 2-碘代苯胺化合物开始也可有效地生产二氢吲哚衍生物。该反应可以按以下顺序进行:(1)通过用三丁基锰酸(II)处理碘苯酚或碘苯胺衍生物形成自由基,(2)自由基环化,以及(3)自由基和锰物质的重组产生烷基锰(II)化合物。证明该反应在催化量的氯化锰 (II) 存在下在大气氧气下进行。锰催化的自由基环化也可以应用于 2-碘乙醛缩醛,在这种情况下,氧的存在是不必要的。