97602-40-9Relevant academic research and scientific papers
Regioselective and Stereoselective Addition of Tetrazole Derivatives to Electron-poor Acetylenic Esters in the Presence of Triphenylphosphine
Ramazani, Ali,Nasrabadi, Fatemeh Zeinali,?lepokura, Katarzyna,Lis, Tadeusz,Joo, Sang Woo
, p. 55 - 64 (2017)
Protonation of the highly reactive 1:1 intermediates produced in the reaction between triphenylphosphine and acetylenic esters by tetrazole derivatives leads to the formation of vinyltriphenylphosphonium salts. The cation of these salts undergoes an addition reaction with the counter anion in CH2Cl2at room temperature to yield the corresponding stabilized phosphorus ylides. Elimination of triphenylphosphine from the stabilized phosphorus ylides leads to the corresponding electron-poor N-vinyl tetrazoles in fairly high yields. Structures of N-vinyl tetrazoles were determined by IR,1H NMR,13C NMR and single crystal X-ray structure analyses. The reaction is fairly regioselective and stereoselective.
Two-step Synthesis of Imidazoles from Activated Alkynes
Casey, Michael,Moody, Christopher J.,Rees, Charles W.,Young, Richard G.
, p. 741 - 746 (2007/10/02)
Conjugate addition of 2-(tri-n-butylstannyl)tetrazoles (1) to activated alkynes gives 1-alkenyltetrazoles (4) and (5) predominantly.Use of the N-tributylstannyl derivatives, rather than the parent tetrazole, gives a high ratio of 1- to 2-alkenyl isomers and avoids the complication of further addition of the tetrazole or the alkyne to the initial adduct.Irradiation of the (Z)- and (E)-1-alkenyltetrazoles (4) and (5) at 254 nm then gives the expected imidazoles in moderate yield.However, 5-phenyl-2-(tri-n-butylstannyl)tetrazole (1a) reacted only slowly with ethyl phenylpropiolate to give ethyl 3,5-diphenylpyrazole-4-carboxylate (8), presumably via the 2-alkenyltetrazole (9) formed in preference to the 1-isomer for steric reasons.
