A Non Expected Alternative Ni(0) Species in the Ni‐Catalytic Aldehyde and Alcohol Arylation Reactions Facilitated by a 1,5‐Diaza‐3,7‐diphosphacyclooctane Ligand

Abstract

For decades there were many attempts to dispense with stoichiometric amounts of metal reagents for the synthesis of secondary alcohols. In 2021, the synthetic results of Newman and collaborators pioneered a synthesis still with metals, but not as reactants. Instead, they serverd as catalytic engines. Here we present a description by means of Density Functional Theory calculations of how this process can occur, and an attempt is made to shed light on the mechanism that facilitates the attainment of secondary alcohols, emphasizing the eternal cross-coupling debate of whether the catalytically active species is Ni(0) or they are really taking shortcuts following the course of Ni(II). Effective Orbital analyses give a clear picture. Furthermore, this paper provides insight not only into the nature of the ligands of the metal catalyst but also the role of the base.

Enhancement of Knölker Iron Catalysts for Imine Hydrogenation by Predictive Catalysis: From Calculations to Selective Experiments

“…To understand the different nature of the first two intermediates, we applied EOS analysis (see technical details in the Supporting Information). , The results obtained for different degrees of substitution of the two phenyls attached to the cyclopentadienone are collected in Table S10. The frontier effective fragment orbitals (EFOs) are for the metal (last occupied (LO) with a pair of electrons assigned) versus the cyclopentadienone ligand (first unoccupied (FU)).…”

Theoretical Mechanistic Study of C(sp3)−C(sp2) Cross‐Coupling by Photoredox‐Mediated Iridium(III)/Nickel(II)/Quinuclidine Triple Catalysis

“…In addition, although the mechanism of Ni(0) as an active species has been proposed to be feasible, [30] neither the "naked" nor ArBr coordinated Ni(0) species can be afforded here to restart this catalytic cycle; see Figure S8 in the Supporting Information.…”

Suzuki–Miyaura Cross-Coupling of Amides by N–C Cleavage Mediated by Air-Stable, Well-Defined [Pd(NHC)(sulfide)Cl2] Catalysts: Reaction Development, Scope, and Mechanism

“…From the next intermediate I6 , reductive elimination allows to release Ph-Cl into solution (overcoming a barrier of 9.4 kcal/mol through TS4 ). Finally, the resulting intermediate I7 with PhCl and the metal weakly interacting each other releases PhCl to obtain the catalytically active Pd(0) species I8 , , relatively unstable, but still 3.0 kcal/mol lower in energy than the pre-catalyst.…”