16336-82-6Relevant articles and documents
Configurational Instability of α-Alkenyl and α-Alkynyl Vinyllithiums. Syntheses of Stereodefined 2-Alkyl-1-en-3-ynes
Miller, Joseph A.,Leong, William,Zweifel, George
, p. 1839 - 1840 (1988)
Metal-halogen exchange of either (Z)-enynyl bromides or (Z)-dienyl bromides by sec-BuLi produces vinyllithiums that are configurationally stable only at temperatures below -120 deg C and -78 deg C, respectively.Allylation of (Z)-enynylalanates with allyl bromide or methylation of (Z)-enynyl bromides with CH3MgI and Fe(acac)3 catalyst furnishes the corresponding 2-alkyl-1-en-3-ynes.
Rhodium(I)-NHC Complexes Bearing Bidentate Bis-Heteroatomic Acidato Ligands as gem-Selective Catalysts for Alkyne Dimerization
Galiana-Cameo, María,Borraz, Marina,Zelenkova, Yaroslava,Passarelli, Vincenzo,Lahoz, Fernando J.,Pérez-Torrente, Jesús J.,Oro, Luis A.,Di Giuseppe, Andrea,Castarlenas, Ricardo
supporting information, p. 9598 - 9608 (2020/07/13)
A series of Rh(κ2-BHetA)(η2-coe)(IPr) complexes bearing 1,3-bis-hetereoatomic acidato ligands (BHetA) including carboxylato (O,O), thioacetato (O,S), amidato (O,N), thioamidato (N,S), and amidinato (N,N), have been prepared by reacti
A copper (I or II)/diethylphosphite catalytic system for base-free additive dimerization of alkynes
Trostyanskaya, Inna G.,Beletskaya, Irina P.
supporting information, p. 148 - 153 (2016/12/23)
Copper (I) or copper (II) salts and oxides promote regioselective head-to-head additive dimerization of aromatic and aliphatic terminal alkynes in the presence a catalytic amount of diethylphosphite. The reaction proceeds under ambient conditions without
Pyridine-enhanced head-to-tail dimerization of terminal alkynes by a rhodium-N-heterocyclic-carbene catalyst
Rubio-Perez, Laura,Azpiroz, Ramon,Di Giuseppe, Andrea,Polo, Victor,Castarlenas, Ricardo,Perez-Torrente, Jesus J.,Oro, Luis A.
supporting information, p. 15304 - 15314 (2013/11/06)
A general regioselective rhodium-catalyzed head-to-tail dimerization of terminal alkynes is presented. The presence of a pyridine ligand (py) in a Rh-N-heterocyclic-carbene (NHC) catalytic system not only dramatically switches the chemoselectivity from alkyne cyclotrimerization to dimerization but also enhances the catalytic activity. Several intermediates have been detected in the catalytic process, including the π-alkyne-coordinated RhI species [RhCl(NHC)(η2-HC ≡CCH2Ph)(py)] (3) and [RhCl(NHC){η2-C(tBu) ≡C(E)CH=CHtBu}(py)] (4) and the RhIII-hydride-alkynyl species [RhClH{-C ≡CSi(Me) 3}(IPr)(py)2] (5). Computational DFT studies reveal an operational mechanism consisting of sequential alkyne Ci£ H oxidative addition, alkyne insertion, and reductive elimination. A 2,1-hydrometalation of the alkyne is the more favorable pathway in accordance with a head-to-tail selectivity. Control plan: Addition of pyridine to rhodium-N-heterocyclic- carbene catalysts not only switches the chemoselectivity from alkyne cyclotrimerization to dimerization, but also enhances the catalytic activity for the formation of 1,3-enynes (see figure). A 2,1-hydrometalation of the alkyne is the more favorable pathway calculated by DFT.