Addition and Cyclization Reactions in the Thermal Conversion of Hydrocarbons with an Enyne Structure, 4. Formation and Rearrangements of Bicyclic C10H8 Aromatics from 1-Phenyl-1-buten-3-yne
作者:Kathrin Schulz、Jörg Hofmann、Gerhard Zimmermann
DOI:10.1002/jlac.199719971217
日期:1997.12
The thermal conversion of 1-phenyl-1-buten-3-yne (1) into the cycloisomerization products naphthalene (2), azulene (3), and 1-methylene-1H-indene (4) has been studied at temperatures between 550 and 1000°C, a reaction time of approximately 0.3 s at 13 Torr (FVP) and at low partial pressures in a quartz flow system. The results obtained by FVP as well as in the presence of chemically modified diluent
NHC ligand was found to be highly efficient for the selectivesemihydrogenation of non‐polar unsaturated compounds using a mixture of a silane and an alcohol as reducing agent. The catalytic system was useful for the selectivesemihydrogenation of internal alkynes to (Z)‐alkenes with suppression of overreduction to the corresponding alkanes. Furthermore, semihydrogenations of terminal alkyne, 1,2‐diene
Stereoselective Synthesis of (Z)-Enynes via Pd(II)/CuI(I)-Catalyzed Cross-Coupling Reaction of bis-Vinylic Tellurides with 1-Alkynes
作者:Gilson Zeni、Paulo H. Menezes、Angélica Venturini Moro、Antonio L. Braga、Claudio C. Silveira、Hélio A. Stefani
DOI:10.1055/s-2001-16799
日期:——
(Z)-bis-Vinylic tellurides undergo direct coupling reaction with terminal alkynes in the presence of palladium (II) at room temperature to give (Z)-enyne systems in good yields.
Enantioselective epoxidation of conjugated dienes and enynes. Trans-epoxides from cis-olefins
作者:Nam Ho Lee、Eric N. Jacobsen
DOI:10.1016/0040-4039(91)80212-o
日期:1991.11
Asymmetric epoxidation of conjugated dienes and enynes catalyzed by (salen)Mn(III) complex 1 takes place with high chemoselectivity to afford monoepoxides exclusively. Reactions of cis-enynes proceed with very high levels of asymmetric induction, with trans-alkynyl epoxides as the major products.
The new iridium(I)-guanidinate complex served as an efficient catalyst for phosphine-dependent selective cross-dimerization between silylacetylene and terminal alkyl- or arylacetylene. Especially, in case of cross-dimerization between silylacetylene and alkylacetylene, E/Z selectivity of resulting enynes could be controlled by changing phosphine.