[2+2] Cycloaddition of 1,3-Dienes by Visible Light Photocatalysis
作者:Anna E. Hurtley、Zhan Lu、Tehshik P. Yoon
DOI:10.1002/anie.201405359
日期:2014.8.18
[2+2] Photocycloadditions of 1,3‐dienes represent a powerful yet synthetically underutilized class of reactions. We report that visiblelight absorbing transition metal complexes enable the [2+2] cycloaddition of a diverse range of 1,3‐dienes. The ability to use long‐wavelength visiblelight is attractive because these reaction conditions tolerate the presence of sensitive functional groups that might
Construction of Complex Cyclobutane Building Blocks by Photosensitized [2 + 2] Cycloaddition of Vinyl Boronate Esters
作者:Spencer O. Scholz、Jesse B. Kidd、Luca Capaldo、Niecia E. Flikweert、Rowan M. Littlefield、Tehshik P. Yoon
DOI:10.1021/acs.orglett.1c00938
日期:2021.5.7
diversification are thus highly desirable. We report herein a photosensitized [2 + 2] cycloaddition with vinyl boronate esters affording straightforward access to complex, densely functionalized cyclobutane scaffolds. Mechanistic studies suggest an activation mode involving energy transfer to the styrenyl alkene rather than the vinyl boronate ester.
the directly dehydrative cross-coupling of allylicalcohols with terminal alkynes was developed. This calcium salt cocatalyst facilitates the oxidative addition of the palladium catalyst (1 mol %) to the C-OH bond. Then, the in situ-generated hydroxide ion deprotonates the terminal alkynes to promote the formation of the allylalkynylpalladium intermediate, liberating water as the only byproduct. This
Chemo-, Regio-, and Stereoselective Silver-Catalyzed Aziridination of Dienes: Scope, Mechanistic Studies, and Ring-Opening Reactions
作者:Josep Llaveria、Álvaro Beltrán、W. M. C. Sameera、Abel Locati、M. Mar Díaz-Requejo、M. Isabel Matheu、Sergio Castillón、Feliu Maseras、Pedro J. Pérez
DOI:10.1021/ja412547r
日期:2014.4.9
of 2,4-diene-1-ols in a chemo-, regio-, and stereoselective manner to give vinylaziridines in high yields by means of the metal-mediated transfer of NTs (Ts = p-toluensulfonyl) units from PhI═NTs. The preferential aziridination occurs at the double bond neighboring to the hydroxyl end in ca. 9:1 ratios that assessed a very high degree of regioselectivity. The reaction with the silver-based catalysts
Rhodium-Catalyzed Synthesis of Eight-Membered Rings
作者:Brenton DeBoef、W. Richard Counts、Scott R. Gilbertson
DOI:10.1021/jo0620462
日期:2007.2.1
Experiments to develop a rhodiumcatalyst for the [4 + 2 + 2] cycloisomerization of dienynes with a second alkyne are described. The generality of the reaction is probed in terms of dienyne structure and alkyne structure. A catalystsystem that provides cyclooctatrienes in greater than 70% yield is reported. Several experiments to determine the nature of the catalyst are described.