Pyridinium triflate catalyzed intramolecular alkyne-carbonyl metathesis reaction of O-propargylated 2-hydroxyarylaldehydes
作者:Manoj Kumar Saini、Harshita Singh Korawat、Shashi Kant Verma、Ashok K. Basak
DOI:10.1016/j.tetlet.2020.152657
日期:2020.12
3,5-Dibromopridinium trifluoromethanesulfonate catalyzes the intramolecular alkyne-carbonyl metathesis reaction of a variety of O-propargylated 2-hydroxyarylaldehydes and ketonesbearingalkyl, aryl and heteroaryl substituted internal alkynes to provide various 3-(hetero)aroyl 2H-chromenes in high yields.
Diversity Oriented Synthesis of Indoloazepinobenzimidazole and Benzimidazotriazolobenzodiazepine from<i>N</i><sup>1</sup>-Alkyne-1,2-diamines
作者:Ravi Kumar、Rajesh K. Arigela、Srinivas Samala、Bijoy Kundu
DOI:10.1002/chem.201502956
日期:2015.12.14
oriented synthesis of two N‐polyheterocycles indoloazepinobenzimidazole and benzimidazotriazolobenzodiazepine from a common N1‐alkyne‐1,2‐diamine building block is described. The approach involves sequential formation of benzimidazole through cyclocondensation and oxidation, which is followed by the formation of either an azepine ring (through alkyne activation and 6‐endo‐dig cyclization, 1,2‐migration
Gold(I)-Catalyzed Cycloisomerization of <i>ortho</i>
-(Propargyloxy)arenemethylenecyclopropanes Controlled by Adjacent Substituents at Aromatic Rings
作者:Wei Fang、Yin Wei、Xiang-Ying Tang、Min Shi
DOI:10.1002/chem.201700600
日期:2017.5.17
Gold(I)‐catalyzed cycloisomerization of ortho‐(propargyloxy)arenemethylenecyclopropanes afforded two different types of products, that is, products of methylenecyclopropane migration and cycloisomerization products of the methylenecyclopropane moiety, controlled jointly by electronic and steric effects of the adjacent substituents. Furthermore, the corresponding cycloisomerization products could be
Borylative Cyclization of 1,6-Allenynes Driven by BCl<sub>3</sub>
作者:Chun-Hua Yang、Xiangkun Sun、Congcong Niu、Zhiwei Zhang、Mingzhu Liu、Fangjie Zheng、Ling Jiang、Xiangtao Kong、Zhantao Yang
DOI:10.1021/acs.orglett.1c03062
日期:2021.10.15
A metal-free intramolecular borylative cyclization of 1,6-allenynes driven by BCl3 was developed. This method provides a general and practical strategy to construct valuable pyrrolidines containing all-carbon quaternary centers or 3,5-dihydroazepine derivatives depending on the substituents of the allene, with conjugative and sterically hindered phenyl groups favoring the latter.
enantioselective synthesis of highly functionalized chiral cyclopent-2-enones by the reaction of alkynyl malonate esters with arylboronic acids is described. These desymmetrizing arylative cyclizations are catalyzed by a chiral phosphinooxazoline/nickel complex, and cyclization is enabled by the reversible E/Z isomerization of alkenylnickel species. The general methodology is also applicable to the synthesis of