Transition-metal-free oxidative cyclization reaction of enynals to access pyrane-2-one derivatives

Author(s):  
Farzaneh Ansari ◽  
Hormoz Khosravi ◽  
Alireza Abbasi Kejani ◽  
Mahsa Armaghan ◽  
Walter Frank ◽  
...  

K2S2O8 is introduced as an oxygen source and C–H functionalization agent in a novel selective metal-free oxidative cyclization of enynals to synthesize α-pyrone derivatives with a relatively broad substrate scope via the formation of two C–O bonds.

Synlett ◽  
2018 ◽  
Vol 29 (07) ◽  
pp. 912-917 ◽  
Author(s):  
Parviz Ranjbar ◽  
Narjes Rezaei ◽  
Ehsan Sheikhi

A metal-free oxidative C(sp3)–N coupling process has been developed for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones. The reaction between primary amines, isatoic anhydride, and benzylic alcohols in the presence of HBr in DMSO at 80 °C affords 2,3-dihydroquinazolin-4(1H)-ones in excellent yields. Under these reaction conditions, benzylic alcohols react with in situ generated bromodimethylsulfonium bromide to form alkoxysulfonium intermediates. These intermediates undergo an oxidative cyclization reaction with primary amines and isatoic anhydride to produce the title products.


RSC Advances ◽  
2016 ◽  
Vol 6 (89) ◽  
pp. 86464-86467 ◽  
Author(s):  
Zhengwang Chen ◽  
Yuelu Wen ◽  
Guotian Luo ◽  
Min Ye ◽  
Qinghao Wang

A highly efficient transition-metal-free cyclization reaction for the synthesis of 2,3-diarylimidazo[1,2-α]pyridines is described.


2021 ◽  
Vol 9 ◽  
Author(s):  
Hua Zhao ◽  
Peng Shen ◽  
Dongru Sun ◽  
Hongbin Zhai ◽  
Yufen Zhao

A Brønsted acid-catalyzed domino ring-opening cyclization transformation of donor-acceptor (D-A) cyclopropanes and 2-naphthols has been developed. This formal [3+2] cyclization reaction provided novel and efficient access to the naphthalene-fused cyclopentanes in the absence of any transition-metal catalysts or additives. This robust procedure was completed smoothly on a gram-scale to afford the corresponding product with comparable efficiency. Furthermore, the synthetic application of the prepared product has been demonstrated by its transformation into a variety of synthetically useful molecules.


2020 ◽  
Vol 40 (6) ◽  
pp. 1529
Author(s):  
Lei Zhang ◽  
Sitian Yuan ◽  
Peng Wang ◽  
Jinbiao Liu

2015 ◽  
Vol 13 (45) ◽  
pp. 10973-10976 ◽  
Author(s):  
Abhishek R. Tiwari ◽  
Akash T. ◽  
Bhalchandra M. Bhanage

A simple and efficient method for the synthesis of 1,3,5-triazines by NIS-catalyzed oxidative cyclization of alcohols with amidines has been developed. The reaction works smoothly under transition-metal and phosphine-free conditions.


2017 ◽  
Vol 41 (13) ◽  
pp. 5280-5283 ◽  
Author(s):  
Haojie Ma ◽  
Cui Guo ◽  
Zhenzhen Zhan ◽  
Guoqiang Lu ◽  
YiXin Zhang ◽  
...  

Herein, a novel and efficient intermolecular cyclization of 2-aminoacetophenones with aldehydes was developed for the synthesis of 2-aryl-4-quinolones through C–C and C–N bond formation.


RSC Advances ◽  
2016 ◽  
Vol 6 (32) ◽  
pp. 27000-27003 ◽  
Author(s):  
Li-Na Guo ◽  
Zhi-Qiang Deng ◽  
Yong Wu ◽  
Jie Hu

An efficient Na2S2O8-promoted radical cyclization reaction of acrylamides with the tertiary cycloalkanols has been developed. This one pot procedure involves a tandem C–C bond cleavage and two C–C bonds formation process.


ChemInform ◽  
2012 ◽  
Vol 43 (48) ◽  
pp. no-no
Author(s):  
Lei Liu ◽  
Jie Hu ◽  
Xiang-Chuan Wang ◽  
Mei-Jin Zhong ◽  
Xue-Yuan Liu ◽  
...  

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