Ni‐Catalyzed Cyclization of Enynes and Alkynylboronates: Atom‐Economical Synthesis of Boryl‐1,4‐dienes
作者:Natalia Cabrera‐Lobera、M. Teresa Quirós、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/chem.201903405
日期:2019.11.18
We report a novel atom-economical Ni-catalyzed cyclization reaction of enynes with alkynylboronates. The reaction employs a non-expensive Ni salt, a phosphine-based ligand and easy-handling alkynylboronates as boron-carbon source. The reaction provides complex fused-bicyclic compounds containing borylated 1,4-cyclohexadienes in high yields in short reaction times, involving the formation of two C-C
Intramolecular [4 + 2] Cycloadditions of 1,3-Enynes or Arylalkynes with Alkenes with Highly Reactive Cationic Phosphine Au(I) Complexes
作者:Cristina Nieto-Oberhuber、Salomé López、Antonio M. Echavarren
DOI:10.1021/ja042257t
日期:2005.5.1
New Au(I) complexes with bulky, biphenyl phosphines are the most reactive catalysts for the cyclizations of enynes. 1,6-Enynes with an aryl ring at the alkyne give 2,3,9,9a-tetrahydro-1H-cyclopenta[b]naphthalenes by a 5-exo-dig cyclization followed by a Nazarov-type ring expansion. 1,8-Dien-3-ynes also cyclize by a 5-exo-dig pathway to form hydrindanes.
Cobalt(I)-Mediated Cycloisomerization of Enynes: Mechanistic Insights
[CpCo(CO)2] catalyzes the cycloisomerization of 1,n-enynes to afford selectively five- and six-membered ring systems in high yields. The factors governing the cyclization have been explored and we have discovered that the reaction associates two different, but complementary, reactivities of the cobalt(I) complexes. By a judicious choice of the substitution of the enyne, it was also possible to isolate