Cyclopentene Annulations of Alkene Radical Cations with Vinyl Diazo Species Using Photocatalysis
作者:Francisco J. Sarabia、Qiankun Li、Eric M. Ferreira
DOI:10.1002/anie.201805732
日期:2018.8.20
A direct (3+2) cycloaddition between alkenes and vinyl diazo reagents using either Cr or Ru photocatalysis is described. The intermediacy of a radicalcation species enables a nucleophilic interception by vinyl diazo compounds, a departure from their traditional electrophilic behavior. A variety of cyclopentenes are synthesized using this method, and experimental insights implicate a direct cycloaddition
[1+1+3] Annulation of Diazoenals and Vinyl Azides: Direct Synthesis of Functionalized 1‐Pyrrolines through Olefination
作者:Vinaykumar Kanchupalli、Sreenivas Katukojvala
DOI:10.1002/anie.201801976
日期:2018.5.4
A dirhodium carboxylate catalyzed [1+1+3] annulation reaction of diazoenals and vinyl azides that gives synthetically important enal‐functionalized 1‐pyrroline derivatives was developed. The reaction involves a novel rhodium‐catalyzed olefination of diazoenals with vinyl azides via electrophilic enal carbenoids, resulting in a new class of enal acrylates. The annulation reaction was used for the direct
Cycloaddition Reactions of Alkene Radical Cations using Iron(III)‐Phenanthroline Complex
作者:Yong Hyun Cho、Jae Hyung Kim、Hyeju An、Kwang‐Hyun Ahn、Eun Joo Kang
DOI:10.1002/adsc.202000191
日期:2020.5.26
oxidation of electron‐rich alkenes using the iron(III)‐phenanthroline complex produced electrophilic alkene radical cations, which promoted efficient radical cation [2+1] cycloaddition reactions with diazo compounds. Subsequent chain propagation afforded tri‐ and tetra‐substituted cyclopropanes. This methodology was also expanded to [3+2] cycloaddition reactions with vinyl diazoesters, validating this sustainable
Rhodium Carbenoid Initiated O–H Insertion/Aldol/Oxy-Cope Cascade for the Stereoselective Synthesis of Functionalized Oxacycles
作者:Kiran Chinthapally、Nicholas P. Massaro、Indrajeet Sharma
DOI:10.1021/acs.orglett.6b03229
日期:2016.12.16
A novel diazo-cascade approach has been developed for the synthesis of nine-membered oxacycles utilizing readily accessible β-hydroxy vinyl ketones and vinyl diazo esters. The Rh(II)-catalyzed cascade reaction begins with carbene O–H insertion followed by an intramolecular aldol cyclization to provide a substituted tetrahydrofuran intermediate that undergoes an oxy-Cope rearrangement to provide functionalized
Gold-Catalyzed C–H Bond Functionalization of Metallocenes: Synthesis of Densely Functionalized Ferrocene Derivatives
作者:Enol López、Giacomo Lonzi、Luis A. López
DOI:10.1021/om500638t
日期:2014.11.10
A convenient process for the direct functionalization of ferrocene that exploits the high electrophilic character of gold–vinyl carbenoids catalytically generated from vinyldiazo compounds and gold complexes is reported. This process takes place with complete regioselectivity (vinilogous reactivity). The synthesis of the corresponding ruthenocene analogues has also been achieved. Preliminary studies