Vinylic tellurides as precursors in a stereoselective and convergent route to Z-enynes and Z-trisubstituted enediynes

Abstract

lítio. Reação dos cianocupratos vinílicos Z assim obtidos com cloreto de zinco fornece presumivelmente espécies mistas de zinco e cobre que reagem com bromoalquinos levando a eninos e enediinos com retenção da configuração Z da ligação dupla.Vinylic tellurides of Z configuration are transformed into higher order Z-vinyl cyanocuprates by transmetallation with higher order lithium dimethyl-or n-butyl(thienyl)cyanocuprates. Reaction of the obtained Z-vinyl cyanocuprates with zinc chloride gives presumably mixed zinc-copper species which react with bromoalkynes leading to enynes and enediynes with retention of the Z double bond configuration.

Vinylic Tellurides: From Preparation to Their Applicability in Organic Synthesis

“…The synthesis of enynes and enediynes was achieved by taking advantage of the tellurium−copper exchange . The reaction was performed by an initial transmetalation of a vinylic telluride with a higher order cyano cuprate, resulting in vinylic cuprates 226 .…”

Iron-catalyzed coupling reactions of vinylic chalcogenides with Grignard reagents

“…The multiple applications of organochalcogenium chemistry have been well described in a number of review articles [1][2][3][4][5][6] and books. [7][8][9][10][11] Functionalized alkynyl [12][13][14][15][16][17][18] and alkenyl [19][20][21][22][23] chalcogenides have a great potential in organic synthesis, since they are valuable intermediates for the selective preparation of several organic compounds.…”

“…The multiple applications of organochalcogenium chemistry have been well described in a number of review articles 1-6 and books. 7-11 Functionalized alkynyl 12-18 and alkenyl [19][20][21][22][23] chalcogenides have a great potential in organic synthesis, since they are valuable intermediates for the selective preparation of several organic compounds.Among the many applications of vinylic selenides, divinylic selenides and vinylic sulfides, the cross-coupling reaction with Grignard reagents catalyzed by Ni 18,24-27 and Pd 28,29 to give the corresponding cross-coupled products, has been described. On the other hand, Pd 19,30 and Ni 24,[31][32][33] catalyzed cross coupling reactions and tellurium/metal exchange reactions [34][35][36][37][38][39][40][41][42] are demonstrative of the usefulness of vinylic tellurides.…”

Synthesis of organothioacrylonitriles and organoselenoacrylonitriles by reaction of 1-Halo-1-chalcogenoalkenes with CuCN

“…Functionalized alkenyl chalcogenides (S, Se and Te) have great potential in organic synthesis, since they are valuable intermediates for the selective preparation of several organic compounds. [1][2][3][4][5][6][7] The synthesis of vinylic chalcogenides has therefore attracted the attention of several research groups, and many novel methods for their preparation have been proposed in the last years. [1][2][3][4][5][6][7] We described practical methodologies for the preparation of vinylic chalcogenides based on Wittig and Wittig-Horner reactions.…”

“…[1][2][3][4][5][6][7] The synthesis of vinylic chalcogenides has therefore attracted the attention of several research groups, and many novel methods for their preparation have been proposed in the last years. [1][2][3][4][5][6][7] We described practical methodologies for the preparation of vinylic chalcogenides based on Wittig and Wittig-Horner reactions. [8][9][10] Studies on the synthesis of α-phenylseleno and α-phenyltelluro acrylonitriles and the chemical reactivity of α-phenylseleno acrylonitriles in reactions with DIBAL-H, amines and in a Diels-Alder-type reaction were also described.…”