Tandem Coupling of Allyl Electrophiles, Alkynes, and Me₃Al or Me₂Zn in the Presence of a Nickel Catalyst

Abstract

The tandem reaction of allyl electrophiles with alkynes and Me3Al or Me2Zn occurred in the presence of a nickel catalyst to give three-component coupling products. This reaction was applied to the coupling with concomitant cyclization of enynyl electrophiles.

Highly Selective Dimerization of Styrenes and Linear Co‐dimerization of Styrenes with Ethylene Catalyzed by a Ruthenium Complex

“…Styrene derivatives 1 a-d were obtained commercially and used without further purification. The spectral data of 2 a, [27] 2 c, [28] 4 a, [28] 4 b, [29] and 4 c [30] were consistent with those reported previously. New compounds, 2 b and 2 d, are characterized below.…”

Nickel‐Catalyzed Reductive Cyclizations and Couplings

“…Although the process was most extensively developed with acetylenic stannanes, organozinc and organoaluminum reagents are also effective participants. [21] The mechanistic proposals for the enone/alkyne couplings have largely focused on the involvement of nickel metallacycles derived from the oxidative cyclization of an enone and an alkyne with nickel(0) (Scheme 9). [9] Once the initial oxidative cyclization occurs to produce metallacycle 16, transmetallation of the main-group organometallic reagent occurs to generate intermediate 17.…”

Nickel‐Catalyzed Arylative Cyclizations of Alkyne‐ and Allene‐Tethered Electrophiles using Arylboron Reagents

“…Overall, two new bonds are formed to give cyclic products, typically of general structure 4 or 7. It should be mentioned that mechanistically different transitionmetal-catalyzed arylative and alkylative cyclizations of alkyneand allene-tethered electrophiles also exist, which proceed via oxidative cyclization to give metallacyclic intermediates, [45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] and these reactions are not covered in this review.…”