Recent advances in tandem selenocyclization and tellurocyclization with alkenes and alkynes

Abstract

Seleno-containing heterocycles exist widely in pharmaceutical molecules and the skeletons of natural products. The addition of organoselenium to alkenes and alkynes via intramolecular tandem selenocyclization is an efficient method for...

PhICl2-Mediated Regioselective and Electrophilic Oxythio/Selenocyanation of o-(1-Alkynyl)benzoates: Access to Biologically Active S/SeCN-Containing Isocoumarins

“…Then the reaction of thiocyanate with thiocyanogen chloride provides (SCN) 2 , which further reacts with the oxidative PhICl 2 to give thiocyanogen chloride ( Tao et al, 2021 ). Next, electrophilic addition between the reactive thiocyanogen chloride with substrate 1a gave rise to intermediate B ( Xing et al, 2019a ; An et al, 2020 ; Hellwig et al, 2020 ; Lynch and Scanlan, 2020 ; Sun et al, 2020 ; Jurinic et al, 2021 ; Slivka and Onysko, 2021 ). Due to the presence of the adjacent electron-withdrawing methoxycarbonyl group which makes the C (sp 2 ) connecting with the Ph substituent more electron-deficient, a favored intramolecular 6-exo cyclization occurred in intermediate B , leading to formation of the cyclic intermediate C .…”

Recent Advances in Catalytic Alkyne Transformation via Copper Carbene Intermediates

“…Transition-metal-catalyzed transformations of carbon-carbon triple bond have been presented as one of the most effective and prominent tools for the construction of functionalized molecules and fine chemicals [ 1 , 2 , 3 , 4 ]. Alkynes have low C sp –H p K a (~25), and the carbon-carbon triple bond could be selectively activated by π-acidic transition metals.…”

TBHP‐Mediated Selenocyclization of N‐Allylbenzamides/Benzthioamides via In‐Situ Generation of “PhSeOH” Species**

“…Thereby, a flight of substantial efforts has been witnessed to materialize innovative synthetic strategies for selenium inclusion. [11][12][13] These efforts include various organoselenium reagents and catalysts.…”

“…Their applications have made quite a mark in pharmaceutical and material sciences for their diverse biological activities [7,8] and fluorescence properties [9,10] respectively, that has allured a large number of synthetic and medicinal chemists in the last few decades. Thereby, a flight of substantial efforts has been witnessed to materialize innovative synthetic strategies for selenium inclusion [11–13] . These efforts include various organoselenium reagents and catalysts.…”