AgSCF3-Mediated Trifluoromethylthiolation/Radical Cascade Cyclization of 1,6-Enynes
摘要:
A AgSCF3-mediated radical cascade cyclization/trifluoromethylthiolation of 1,6-enynes triggered by a C-C triple bond is developed. This protocol also provides another opportunity to construct a valuable trifluoromethylthio-substituted polycyclic fluorene system through the formations of one C-SCF3 bond and two C-C bonds in a single step.
Sulfonylative and Azidosulfonylative Cyclizations by Visible-Light-Photosensitization of Sulfonyl Azides in THF
作者:Shaoqun Zhu、Atchutarao Pathigoolla、Grace Lowe、Darren A. Walsh、Mick Cooper、William Lewis、Hon Wai Lam
DOI:10.1002/chem.201704380
日期:2017.12.11
generation of sulfonyl radicals from sulfonyl azides using visible light and a photoactive iridium complex in THF is described. This process was used to promote sulfonylative and azidosulfonylative cyclizations of enynes to give several classes of highly functionalized heterocycles. The use of THF as the solvent is critical for successful reactions. The proposed mechanism of radical initiation involves
Described herein is a visible‐light‐mediated atom‐transfer radical cyclization (ATRC) using 1,6‐enynes as substrates. The sulfonyl chlorides not only served as sulfonyl radical sources but also provided a chlorine atom to enable the formation of highly functionalized cyclic products. This visible‐light‐mediated photocatalytic method is a mild and practical strategy for synthesizing chloroalkyl‐substituted
Gold(I)-Catalyzed Intramolecular [4+2] Cycloadditions of Arylalkynes or 1,3-Enynes with Alkenes: Scope and Mechanism
作者:Cristina Nieto-Oberhuber、Patricia Pérez-Galán、Elena Herrero-Gómez、Thorsten Lauterbach、Cristina Rodríguez、Salomé López、Christophe Bour、Antonio Rosellón、Diego J. Cárdenas、Antonio M. Echavarren
DOI:10.1021/ja075794x
日期:2008.1.1
The cyclizations of enynes substituted at the alkyne gives products of formal [4+2] cyclization with Au(I) catalysts. 1,8-Dien-3-ynes cyclize by a 5-exo-dig pathway to form hydrindanes. 1,6-Enynes with an aryl ring at the alkyne give 2,3,9,9a-tetrahydro-1H-cyclopenta[b]naphthalenes by a 5-exo-dig cyclization followed by a Friedel-Crafts-type ring expansion. A 6-endo-dig cyclization is also observed
Synthesis of cyclic allyl vinyl ethers using Pt(II)-catalyzed isomerization of oxo-alkynes
作者:Zezhou Wang、Xi Lin、Rudy L. Luck、Garrett Gibbons、Shiyue Fang
DOI:10.1016/j.tet.2009.01.065
日期:2009.3
Several alkynyl epoxides and one alkynyl allyl alcohol were isomerized to cyclic allylvinylethers (3,4-dihydro-2H-1,4-oxazines) using PtCl2 as the catalyst. Three of these allylvinylethers were converted to 2-hydroxymorpholine derivatives by hydrolysis and two were converted to piperidine derivatives by thermal Claisenrearrangement.
使用PtCl 2作为催化剂,将几种炔基环氧化物和一种炔基烯丙醇异构化为环状烯丙基乙烯基醚(3,4-二氢-2 H -1,4-恶嗪)。这些烯丙基乙烯基醚中的三种通过水解转化为2-羟基吗啉衍生物,而两种通过热克莱森重排转化为哌啶衍生物。
Tetranuclear Dicationic Aurophilic Gold(I) Catalysts in Enyne Cycloisomerization: Cooperativity for a Dramatic Shift in Selectivity
Towards specific “cluster-like” reactivity? Ligands pre-organizing gold centers in a constrained environment, assisted by aurophilic interactions, push further the selectivity not achieved by mono- and digold complexes from previously unseen cooperative tetragold catalysis.