Addition d'hétérocycles azotés aux alcynes arylés; synthèse de N‐styrylazoles

Abstract

Les azoles (pyrazoles, imidazoles) se fixent sur la triple liaison du phénylacétylène et du phénylméthylacétylène selon des réactions d'addition, stéréosélectives et stéréospécifiques. Ceci permet la synthèse de divers styrylazoles.

Direct Electrophilic Silylation of Terminal Alkynes

“…Silylalkynes are important synthons for organic chemistry alkoxy-, and acyloxysilanes, silyl sulfonates, siloxanes, or silylimidazoles . However, more attractive, complementary methods not involving the use of strong bases are not well developed.…”

Synthesis and Photophysical Properties of N‐Styrylazinones.

“…As part of our research program for the search of novel fluorescent molecules, we attempted to synthesize some N-styrylheteocycles. Although synthetic methods leading to some styryldiazines and few styrylazinones have been reported [38][39][40][41][42][43][44][45][46][47][48][49][50][51], they have some disadvantages such as low selectivity and low yield. Therefore, we tried synthesis of N-styrylazinones according to the synthetic sequence outlines depicted in Schemes 2-4.…”

Styrylpyrazoles: Properties, Synthesis and Transformations

“…In 1978, Burgeois et al described a lithium-catalyzed stereospecific and stereoselective addition of the N–H bond of pyrazole 20 to phenylacetylene, as a method to prepare 1-styrylpyrazoles 21 ( Scheme 2 ) [ 54 ]. Under such conditions, ( Z )-1-styryl-1 H -pyrazole ( 21a ) and ( Z )-5-amino-1-styryl-1 H -pyrazole ( 21b ) were obtained in 60% and 55% yield, respectively.…”

“…Addition of pyrazole 20 to alkynes to produce (Z)-1-styrylpyrazoles 21-23[54,55].The role of two ruthenium complexes [Ru(dppe)(PPh3)(CH3CN)2Cl][BPh4] (24) (dppe = diphenylphosphinoethane) and [Ru(dppp)2(NCCH3)Cl][BPh4] (25) (dppp = diphenylphosphinopropane) as efficient catalysts in the regio-and stereoselective addition of…”