Metal‐Free ipso‐Halocyclization of N‐Arylpropynamides Using Hypervalent Iodine(III) Reagents under Aqueous Condition
作者:Pankaj Jangir、Kalu Ram Bajya、Akshay S. Pathare、Mohammad Sodoor、Rinku Saini、Mukesh Purohit、Sermadurai Selvakumar
DOI:10.1002/ejoc.202400203
日期:2024.5.27
An efficient intramolecular ipso-halocyclization of para-unsubstituted N-arylpropynamides proceeds using readily available hypervalentiodinereagents as oxidant and potassium halides as halogen source under aqueous medium. This method shows a broad substrate scope and doesn't require any metal catalysts.
Intramolecular <i>ipso</i>-Halocyclization of 4-(<i>p</i>-Unsubstituted-aryl)-1-alkynes Leading to Spiro[4,5]trienones: Scope, Application, and Mechanistic Investigations
作者:Bo-Xiao Tang、Yue-Hua Zhang、Ren-Jie Song、Dong-Jun Tang、Guo-Bo Deng、Zhi-Qiang Wang、Ye-Xiang Xie、Yuan-Zhi Xia、Jin-Heng Li
DOI:10.1021/jo300037n
日期:2012.3.16
A new, general method for the synthesis of spiro[4,5]trienores is described by the intramolecular ipso-halocyclization of 4-(p-unsubstituted-aryl)-1-alkynes. In the presence of halide electrophiles, a variety of 4-(p-unsubstituted-aryl)-1-alkynes underwent the intramolecular ipso-halocyclization with water smoothly, affording the corresponding halo-substituted spiro[4,5]trienones in moderate to good yields. The obtained spiro[4,5]trienones can be applied in constructing the azaquaternary tricyclic skeleton via Pd-catalyzed Heck reaction. Notably, the prepared spiro[4,5]trienones and azaquaternary tricycles are of importance in the areas of pharmaceuticals and agrochemicals. The mechanism of the intramolecular ipso-halocyclization reaction is also discussed according to the O-18-labeling experiments and DFT calculations.