94209-23-1Relevant academic research and scientific papers
The first chemoselective tandem acylation of the Blaise reaction intermediate: A novel method for the synthesis of α-acyl-β-enamino esters, key intermediate for pyrazoles
Sung Chun, Yu,Kon Lee, Ki,Ok Ko, Young,Shin, Hyunik,Lee, Sang-Gi
supporting information; experimental part, p. 5098 - 5100 (2009/03/11)
The Blaise reaction intermediate, a zinc bromide complex of β-enamino ester, could be activated in situ by addition of a stoichiometric or catalytic amount of n-BuLi to allow chemoselective tandem C2-acylation providing α-acyl-β-enamino esters, which are
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.
