Evaluation of Organic Hydride Donors as Reagents for the Reduction of Carbon Dioxide and Metal-Bound Formates

Abstract

A variety of organic hydride donors (OHDs) have been tested as reagents for the transfer of hydride to iron formato complexes in the activation and reduction of carbon dioxide. Theoretical calculations show that the selection of OHD and solvent is crucial when planning systems involving OHD cooperativity. Strong consideration is given to the likelihood that metal centers may deactivate formate to hydride attack, since, in general, the formate group has more resonance stabilization energy when complexed to a metal center compared to an organoformate or formic acid. It is experimentally demonstrated that 1,2dihydropyridine is not a competent reducing agent for carbon dioxide.

Iron-Catalyzed Homogeneous Hydrogenation with Precise Temperature-Governed Chemoselectivity.

“…6, equation 4) which was in agreement with the conditions for catalytic hydrogenation of aldehydes. Based on this phenomenon and literatures about Fe(II) tetraphosphine dihydride complexes 30,31 , we tentatively assumed that Fe-2 is the active species on the catalytic cycle. A systematic investigation to probe the catalytic cycle is currently undertaken.…”

“…6, Fe-1). Fe-1 is a diamagnetic iron complex with two doublet peaks in 31 P NMR spectrum (δ 87.4 and 72.6, P-P J = 87.5 Hz). Reduction of this bromide complex with lithium aluminum hydride gave a transdihydride complex Fe-2 (Fig.…”

NAD(P)H-Inspired CO2 Reduction Based on Organohydrides

“…The mechanism by which pyridinium derivatives facilitate electrochemical CO 2 R is indeed a subject of ongoing scientific debate, incorporating both theoretical models and experimental data. 136 Nonetheless, the pyridine or pyridinium species have been identified as the active catalytic components in the electrochemical and photoelectrochemical CO 2 R to HCOOH or MeOH. More in-depth mechanistic investigations should be conducted, which will provide valuable insights into the reaction pathways and intermediates involved in organohydrides-mediated CO 2 R. Understanding these mechanisms is critical for optimizing reaction performance and guiding the rational design of new organohydride-based catalysts.…”

“…The mechanism by which pyridinium derivatives facilitate electrochemical CO 2 R is indeed a subject of ongoing scientific debate, incorporating both theoretical models and experimental data . Nonetheless, the pyridine or pyridinium species have been identified as the active catalytic components in the electrochemical and photoelectrochemical CO 2 R to HCOOH or MeOH.…”

Synthesis of DBpin using Earth-abundant metal catalysis

“…B2pin2 was purchased from Fluorochem and recrystallised before use. All cobalt and iron species were prepared according to reported procedures [23,24,[26][27][28].…”