Lewis Acid Mediated Intramolecular C–C Bond Formation of Alkyne-Epoxide Leading to Six-Membered Nitrogen and Oxygen Heterocycles
作者:Priya Ghosh、Pipas Saha、Somasekhar Bondalapati、Kiran Indukuri、Anil K. Saikia
DOI:10.1021/jo402550e
日期:2014.5.2
Intramolecular C–C bond formation of oxygen- and nitrogen-tethered alkynes and epoxide mediated by Lewis acid under ambient conditions is described. A simple procedure for the synthesis of 3,6- and 5,6-dihydropyrans and 3,4-dehydropiperidines from acyclic building blocks in good yields without using any transition metal is shown.
Alkene <i>versus</i> alkyne reactivity in unactivated 1,6-enynes: regio- and chemoselective radical cyclization with chalcogens under metal- and oxidant-free conditions
作者:Mohana Reddy Mutra、Vishal Suresh Kudale、Jing Li、Wu-Hsun Tsai、Jeh-Jeng Wang
DOI:10.1039/d0gc00321b
日期:——
light-promoted alkene vs. alkyne regio- and chemoselective radical cascade cyclization of electronically unbiased 1,6-enynes with chalcogens to synthesize substituted pyrrolidines bearing chalcogens. The reaction generated three new bonds, namely, C–SO2, C–C, and C–Se under extremely mild conditions. Furthermore, we achieved regio- and chemoselective mono-addition of aromatic thiophenols with unactivated 1,6-enynes
Palladium-catalyzed oxidative 6-exo-trig cyclization of 1,6-enynes: facile synthesis of bicyclo[4.1.0]heptan-5-ones
作者:Bang Liu、Ren-Jie Song、Xuan-Hui Ouyang、Yang Li、Ming Hu、Jin-Heng Li
DOI:10.1039/c5cc04300j
日期:——
We here describe a new palladium-catalyzed oxidative 6-exo-trig cyclization of 1,6-enynes at room temperature using tBuONO as oxidant for the synthesis of 3-bicyclo[4.1.0]heptan-5-ones. This cascade strategy achieves hydration, cyclization and...
Time and Atom Economical Regio‐ and Chemoselective Radical Cyclization of Unactivated 1,6‐Enynes Under Metal‐ and Oxidant‐Free Conditions
作者:Mohana Reddy Mutra、Jing Li、Yu‐Ting Chen、Jeh‐Jeng Wang
DOI:10.1002/chem.202200742
日期:2022.7.26
Chemical economics! Highly substituted five-membered heterocyclic compounds were synthesized from unactivated 1,6-enynes and sulfonyl halides undermetal, additive-free reaction conditions. These transformations can minimize chemical waste, save time, and simplify practical aspects compared to exiting protocols.
Tandem Platinum Dichloride Catalysis and Thermal Reaction of Enynes: Versatile Synthetic Platform Based on Bicyclo[4.1.0]hept‐2‐enes
作者:Sun Young Kim、Yujung Park、Sori Son、Young Keun Chung
DOI:10.1002/adsc.201100694
日期:2012.1
tandem platinum dichloride‐catalyzedcycloisomerization and rearrangement reaction of enynes leads to the formation of 2,4‐pentadienals, 1‐aryl‐tetrahydro‐1H‐indenes, or 3‐methylene‐4‐vinylcyclohex‐1‐enes; depending upon the substituent(s) and tether group of the enynes, the platinum dichloride‐catalyzedcycloisomerization products, bicyclo[4.1.0]hept‐2‐enes, undergo a Claisen rearrangement, a 1,5‐hydrogen