Mechanistic Applications of Nonlinear Effects in First‐Row Transition‐Metal Catalytic Systems

Abstract

Comprehensive SummaryKnowledge of asymmetric catalytic reaction mechanism is very important for rational design and synthesis of new chiral catalysts or catalytic systems with high catalytic activity and stereoselectivity. The studies of nonlinear effect have attracted wide attentions as a simple and practical mechanistic tool to probe complex asymmetric catalytic reactions. This review documents the application of the study of nonlinear effects on how to reveal the mechanism in asymmetric catalytic reactions that were catalyzed by the first‐row transition‐metals in the last decade and gives a brief discussion on the different models of nonlinear effect.This article is protected by copyright. All rights reserved.

Regio‐ and Atroposelective Ring‐Opening of 1H‐Benzo[4,5]oxazolopyridinones

“…Correlation analysis was also carried out, revealing a linear relation between the enantiopurities of product 2 a and ligand L8 (Figure 2a). The results provided further evidence of our preference for the active form of nickel catalyst being a Ni : ligand (1 : 1) monomer, although a linear relationship cannot yield any absolute conclusion [64,65] . According to previous mechanistic research on Ni‐catalyzed C−O bond activation, [66–70] a concise catalytic cycle was proposed in Figure 2b.…”

“…The results provided further evidence of our preference for the active form of nickel catalyst being a Ni : ligand (1 : 1) monomer, although a linear relationship cannot yield any absolute conclusion. [64,65] According to previous mechanistic research on Ni-catalyzed CÀ O bond activation, [66][67][68][69][70] a concise catalytic cycle was proposed in Figure 2b. In the present phosphine-oxazoline ligand L8, an active nickel(0) catalyst A was formed upon treatment with Ph 4 ZnLi 2 .…”

IronIII-catalyzed asymmetric inverse-electron-demand hetero-Diels–Alder reaction of dioxopyrrolidines with simple olefins

“…There was obvious hyperchromic effect upon mixing Fe(OTf) 3 with dioxopyrrolidine A1, especially in the presence of the L 3 -TQEt 2 Ad ligand. In addition, the investigation of relationship between ee value of L 3 -TQEt 2 Ad and that of C1 showed a self-evident linear effect, 24 implying catalytically active species was likely to be the monomeric complex of Fe(OTf) 3 and L 3 -TQEt 2 Ad ( Fig. 1b ).…”

Regio‐ and Atroposelective Ring‐Opening of 1H‐Benzo[4,5]oxazolopyridinones

“…The results provided further evidence of our preference for the active form of nickel catalyst being a Ni : ligand (1 : 1) monomer, although a linear relationship cannot yield any absolute conclusion. [64,65] According to previous mechanistic research on Ni-catalyzed CÀ O bond activation, [66][67][68][69][70] a concise catalytic cycle was proposed in Figure 2b. In the present phosphine-oxazoline ligand L8, an active nickel(0) catalyst A was formed upon treatment with Ph 4 ZnLi 2 .…”