78049-76-0Relevant academic research and scientific papers
Nickel-catalyzed site- and stereoselective reductive alkylalkynylation of alkynes
Jiang, Yi,Pan, Jiaoting,Yang, Tao,Zhao, Yu,Koh, Ming Joo
, p. 993 - 1005 (2021)
The development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined di-functionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides, and redox-active N-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to an 89% yield as single regio- and E isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered N-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. This study underscores the crucial role of redox-active esters as superior alkyl group donors compared with haloalkanes in reductive alkyne dicarbofunctionalizations.
COMPLEXES OF TRANSITION METALS IN THE CHEMISTRY OF CONJUGATED SYSTEMS. I. CATALYTIC ADDITION OF ORGANOMAGNESIUM AND ORGANOLITHIUM COMPOUNDS TO ENYNES AND THEIR DERIVATIVES
Zubritskii, L. M.,Fomina, T. N.,Bal'yan, Kh. V.
, p. 63 - 71 (2007/10/02)
Hydrocarbons with a conjugated system of double and triple bonds are capable of catalytic addition of arylmagnesium halides and aryllithiums at the triple bond in the presence of the salts and complexes of transition metals of group VIII.The β-diketonate complexes of Ni(II) and Fe(III) have the greatest activity.In the case of aryllithiums uncatalyzed addition reactions occur as well.Under the same conditions aliphatic Grignard reagents and alkyllithiums give a complex mixture of addition, reduction and oligomerizatin products.The direction of addition is determined solely by the character of substitution in the enyne system.The product yields are also determined by the nature of the metal and of the ligands in the catalyst and by the character of the organomagnesium and organolithium compound.The effect of polar and steric factors of the substituents at the triple bond in the alkyl, aryl, and trialkylsilyl series leads to a change in the direction of coordination and to the formation of the products from addition at the double bond.
