Regio- and Stereoselective Diarylation of 1,3-Dienes via Ni/Cr Cocatalysis

Abstract

Through the formation of the thermodynamically favored Cr(III)−O bond, the Nozaki−Hiyama−Kishi reaction has been widely applied in the functionalization of carbonyl compounds with the help of Ni catalysis. Herein, a divergent regio-and stereoselective diarylation of dienes has been developed under Ni/Cr cocatalysis without the inherent driving force for the formation of polar metal alkoxides. Preliminary experimental studies have been conducted to elucidate the key roles of Ni, Cr, and redox-active bis(imino)pyridine (PDI) ligands. The proposed mechanism suggests that the newly formed C−C bond of this diarylation was created by organonickel species instead of organochromium species.

Nickel‐Catalyzed Cross‐Electrophile 1,2‐Silyl‐Arylation of 1,3‐Dienes with Chlorosilanes and Aryl Bromides

“…Despite these promising advances, many remain to be investigated. For example, a) non‐alkylative reaction remains largely unexplored; [7] b) nonradical difunctionalization remains to be explored, although it has been well documented by the conventional methods; [3] and c) the three‐component reaction of 1,3‐dienes is yet to be disclosed [8, 9] . In this manuscript, we demonstrate these possibilities by silylative difunctionalization of 1,3‐dienes using chlorosilanes.…”

Nickel-catalyzed divergent Mizoroki–Heck reaction of 1,3-dienes

“…Besides the desired diarylation product, minor Heck or hydroarylation products were also observed (Fig. 1b ) 59 . Similar side-products have also been observed by Koh et al in their recent work on diarylation of aliphatic 1,3-dienes 60 .…”

“…Similar side-products have also been observed by Koh et al in their recent work on diarylation of aliphatic 1,3-dienes 60 . Inspired by these precedents [40][41][42][43][44][45][46][47][48][49][50][51][52][53][54][55][56][57][58][59] , we envisioned whether it would be possible to divert the reactivity of Ni−Ar species from diarylation to Heck reaction of dienes. Given the four reactive sites of 1,3-dienes, it will also be possible to obtain divergent regioisomers on Heck reaction.…”

Mechanistic Investigation into the Regio-Controllable Hydroallylations of Alkynes with Allylborons under Pd-Based Synergetic Catalyses

“…Significance of skipped dienes (e.g., 1,4- or 1,5-dienes) in numerous natural products and bioactive compounds has spurred the evolution of various synthetic strategies. Tremendous effort has been devoted to transitional-metal catalyzed cross-coupling reactions, among which the hydroallylations of alkynes have attracted much attention due to their extraordinary efficiency and being free of the substrate preactivation . However, in contrast to the formations of 1,4-diene motifs, those of 1,5-dienes via hydroallylation of alkynes have been rarely investigated.…”