Radical-mediated carboselenation of terminal alkynes under mild conditions

Abstract

A direct carboselenation of terminal alkynes with diorganyl diselenides and azobisisoalkylcarbonitriles via a radical process has been disclosed, affording the corresponding (E)-γ-seleno-substituted allyl nitriles with excellent regioselectivity and stereoselectivity. This...

Thermodynamic Evaluation on Alkoxyamines of TEMPO Derivatives, Stable Alkoxyamines or Potential Radical Donors?

“…To better understand the potential radical-donating ability of alkoxyamines in view of BDEs, the BDEs of common radical donors or initiators are shown in Scheme 5. [15][16][17][18][19][20][21] As can be seen from Scheme 5, the trifluoromethyl iodide (I-CF 3 ) [21] and diphenyl disulfide (PhS-SPh) [16] are good radical precursors of * CF 3 and PhS * under the condition of a solution, heat or hv in chemical synthesis, whose BDEs are 54.8 and 51.2 kcal/mol, respectively. Besides, ethyl peroxide [EtO-OEt, BDE(OÀ O) = 38.7 kcal/mol] could produce EtO * by breaking peroxy bond (OÀ O) when heated or violently vibrated.…”

Selective Access to Functional Fluoroenones via Palladium-Catalyzed Selenofluoroalkylacylation of Terminal Alkynes

“…Diselenides usually act as a radical initiator and carbon radical capture agent in alkyne radical addition reactions . In continuation of our interest in radical-initiated difunctionalization of unsaturated hydrocarbons, , we believed that the selenoacylation of terminal alkynes with trifluoroacyl radicals and diselenide agents would offer a desirable way to access functional fluoroenones. However, such a synthetic purpose needs to address at least two challenges: (1) The inhibition of trifluoroacyl radical decarbonylation to result in undesired side reactions .…”

Catalyst free one pot three components synthesis of 2-iminothiazoles from nitroepoxides and thiourea

“…[29][30][31] have been utilized in the reaction with nitroepoxides for the synthesis of valuable heterocyclic compounds including imidazoles, 1,3-thiazoles, benzodiazepines, thiazoline-2-thiones, and pyrazines.Multicomponent reactions (MCRs) provide simple access to complex molecules in a one-pot. MCRs have several advantages such as generation of several bonds in a single operation, avoiding the need for isolation and purification of reaction intermediates, saving in time, materials, solvents and energy [32][33][34][35][36][37][38] . For this purpose, multicomponent reaction of isothiocyanates with amines in the presence of an electrophile is an efficient strategy for the synthesis of 2-imino-1,3-thiazolines.…”

“…Multicomponent reactions (MCRs) provide simple access to complex molecules in a one-pot. MCRs have several advantages such as generation of several bonds in a single operation, avoiding the need for isolation and purification of reaction intermediates, saving in time, materials, solvents and energy [32][33][34][35][36][37][38] . For this purpose, multicomponent reaction of isothiocyanates with amines in the presence of an electrophile is an efficient strategy for the synthesis of 2-imino-1,3-thiazolines.…”