Selective reductive coupling of carbon monoxide

Wayland, Bradford B.; Sherry, Alan E.; Coffin, Virginia L.

doi:10.1039/c39890000662

Cited by 39 publications

(25 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The product (52) was not amenable to NMR or solid state characterisation and was inferred through IR studies on 12 CO and 13 CO isotopomers. 39 In 2016, Kinjo and co-workers reported the isolation of the boryllithium compound 53 (Scheme 14). Insertion of CO into the B-Li bond of this highly reactive species forms the boraacyllithium 54, with tautomerises to 54′.…”

Section: (Iii) Reduction Of Co With M-m B-li Sivsi and Bub Bondsmentioning

confidence: 99%

Cooperative strategies for CO homologation

Kong

Crimmin

2020

Dalton Trans.

View full text Add to dashboard Cite

show abstract

Section: (Iii) Reduction Of Co With M-m B-li Sivsi and Bub Bondsmentioning

confidence: 99%

Cooperative strategies for CO homologation

Kong

Crimmin

2020

Dalton Trans.

View full text Add to dashboard Cite

show abstract

“…Molecular systems have been studied extensively to gain insight into the steps of reductive CO coupling chemistry . Leveraging strong M–O interactions, − insertion into early transition-metal hydride bonds, − inducing radical character at carbon, , and electrophilic functionalization − have all proven viable strategies for CO reduction, C–O bond cleavage, and C–C bond formation. The addition of silyl electrophiles to electron-rich dicarbonyl complexes forms bound bis(siloxy)acetylene units, − ,, a two-electron reduced CO coupling product.…”

Section: Introductionmentioning

confidence: 99%

Mechanism of Molybdenum-Mediated Carbon Monoxide Deoxygenation and Coupling: Mono- and Dicarbyne Complexes Precede C–O Bond Cleavage and C–C Bond Formation

Buss

Agapie

2016

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Deoxygenative coupling of CO to value-added C≥2 products is challenging and mechanistically poorly understood. Herein, we report a mechanistic investigation into the reductive coupling of CO, which provides new fundamental insights into a multielectron bond-breaking and bond-making transformation. In our studies, the formation of a bis(siloxycarbyne) complex precedes C–O bond cleavage. At −78 °C, over days, C–C coupling occurs without C–O cleavage. However, upon warming to 0 °C, C–O cleavage is observed from this bis(siloxycarbyne) complex. A siloxycarbyne/CO species undergoes C–O bond cleavage at lower temperatures, indicating that monosilylation, and a more electron-rich Mo center, favors deoxygenative pathways. From the bis(siloxycarbyne), isotopic labeling experiments and kinetics are consistent with a mechanism involving unimolecular silyl loss or C–O cleavage as rate-determining steps toward carbide formation. Reduction of Mo(IV) CO adducts of carbide and silylcarbyne species allowed for the spectroscopic detection of reduced silylcarbyne/CO and mixed silylcarbyne/siloxycarbyne complexes, respectively. Upon warming, both of these silylcarbynes undergo C–C bond formation, releasing silylated C2O1 fragments and demonstrating that the multiple bonded terminal MoC moiety is an intermediate on the path to deoxygenated, C–C coupled products. The electronic structures of Mo carbide and carbyne species were investigated quantum mechanically. Overall, the present studies establish the elementary reactions steps by which CO is cleaved and coupled at a single metal site.

show abstract

“…The [(por)Rh(CO)] • (por = porphyrin) radicals, featuring bent Rh–CO geometries, were reported by Wayland via the coordination of CO to [(por)Rh(II)] • metalloradical . Considerable spin density was delocalized onto the bent CO ligand as confirmed by electron paramagnetic resonance (EPR) measurements. , The bent CO ligand showed radical-like reactivity with triorganostannanes to form rhodium formyl complexes (Rh–CHO), with [(por)Rh(II)] • to form dirhodium ketone (Rh–C(O)–Rh), with alcohols to form alkoxyl carbonyl rhodium (Rh–C(O)–OR), and dimerized to form rhodium α-diketone (Rh–C(O)–C(O)–Rh). ,− However, further transformations of the activation products are disfavored under thermal conditions because of the rigid planar porphyrin ligand, which blocked the requisite vacant coordination sites for migration–insertion and reductive elimination. Recent progress in our laboratory revealed that photolysis of Rh–C bonds might be a productive route to overcome their thermal stability and obtain catalytic turnover in systems involving those novel porphyrin rhodium complexes. − …”

Section: Introductionmentioning

confidence: 78%

Production of Formamides from CO and Amines Induced by Porphyrin Rhodium(II) Metalloradical

Zhang

et al. 2018

J. Am. Chem. Soc.

View full text Add to dashboard Cite

It is of fundamental importance to transform carbon monoxide (CO) to petrochemical feedstocks and fine chemicals. Many strategies built on the activation of C≡O bond by π-back bonding from the transition metal center were developed during the past decades. Herein, a new CO activation method, in which the CO was converted to the active acyl-like metalloradical, [(por)Rh(CO)] (por = porphyrin), was reported. The reactivity of [(por)Rh(CO)] and other rhodium porphyrin compounds, such as (por)RhCHO and (por)RhC(O)NH Pr, and corresponding mechanism studies were conducted experimentally and computationally and inspired the design of a new conversion system featuring 100% atom economy that promotes carbonylation of amines to formamides using porphyrin rhodium(II) metalloradical. Following this radical based pathway, the carbonylations of a series of primary and secondary aliphatic amines were examined, and turnover numbers up to 224 were obtained.

show abstract

Selective reductive coupling of carbon monoxide

Cited by 39 publications

References 1 publication

Cooperative strategies for CO homologation

Cooperative strategies for CO homologation

Mechanism of Molybdenum-Mediated Carbon Monoxide Deoxygenation and Coupling: Mono- and Dicarbyne Complexes Precede C–O Bond Cleavage and C–C Bond Formation

Production of Formamides from CO and Amines Induced by Porphyrin Rhodium(II) Metalloradical

Contact Info

Product

Resources

About