A novel palladium(0)‐catalyzed dearomative cyclization reaction of bromophenols with (1,n)‐diynes has been developed for building two new types of tricyclic architectures containing a quaternary carbon center. This method employs inexpensive bromophenols, and easily accessible tethered diynes. It exhibits a broad substrate scope and tolerates various functional groups. Preliminary results with commercially
Rh<sup>III</sup>-Catalyzed Synthesis of Cyclopenta[<i>b</i>]carbazoles via Cascade C–H/C–C Bond Cleavage and Cyclization Reactions: Using Amide as a Traceless Directing Group
作者:Yanwei Wang、Bin Li、Baiquan Wang
DOI:10.1021/acs.orglett.9b03969
日期:2020.1.3
Rhodium-catalyzed cascade C-H/C-C cleavage and cyclization reactions of 3-amide substituted indoles with diynes to construct cyclopenta[b]carbazoles have been developed. A strategy amide worked as a novel traceless directing group along with C-C bondcleavage via Friedel-Crafts-retro reaction has been disclosed in this protocol. This method exhibits a broad substrate scope and tolerates various functional
The first catalytic synthesis of exocyclic 1,3-dienylphosphine oxides was achieved by the ruthenium-catalyzed selective hydrophosphinylative cyclization of 1,6-diynes. A plausible mechanism involving a ruthenacyclopentatriene intermediate is proposed on the basis of the DFT calculations of model ruthenium complexes.
Photoinduced Radical Cyclization of 1,6‐Diynes: Rapid Access to Highly Substituted Carbocyclic and Heterocyclic Compounds
作者:Mohana Reddy Mutra、Yu‐Ting Chen、Jeh‐Jeng Wang
DOI:10.1002/adsc.202300013
日期:——
sulfonyl radical-triggered cyclization of 1,6-dynes without metals, oxidants, or additives. During the reaction, three new bonds are formed (−SO2−C, C−C, and C−I/C−Se−) under mild conditions, with excellent selectivity. The conversion is temporally and atomically economical and is easy to handle even on a gram scale. Detailed mechanistic studies showed that the reaction proceeds via a radical pathway
A novel oxygen-atom-transfer process enables the catalytic [2 + 2 + 1] synthesis of bicyclic furans from alpha,omega-diynes with DMSO. [CpRu(AN)(3)]PF6 catalyzed the transfer oxygenative cyclization of diynes with aryl terminal groups, while those of diynes with alkyl terminal groups were effectively promoted by the corresponding Cp* complex. A mechanism for bicyclic furan formation via a ruthenacyclopentatriene was proposed on the basis of both experimental and theoretical studies.