Tucci, Gregory C. published the artcileNickel-Mediated Formation of Thio Esters from Bound Methyl, Thiols, and Carbon Monoxide: A Possible Reaction Pathway of Acetyl-Coenzyme A Synthase Activity in Nickel-Containing Carbon Monoxide Dehydrogenases, Computed Properties of 22693-41-0, the publication is Journal of the American Chemical Society (1995), 117(24), 6489-96, database is CAplus.
Current mechanistic proposals for the acetyl-CoA synthase activity of nickel-containing carbon monoxide dehydrogenases (CH3-THF + CoA¡¤SH ¡ú CoA¡¤SCOCH3 + THF; THF = tetrahydrofolate, CoA¡¤SH = CoA) implicate a Ni catalytic center and the steps [Ni-CH3] ¡ú [Ni-COCH3] ¡ú CoA¡¤SCOCH3. The second step presumably involves attack by the sulfur nucleophile of CoA at the acyl carbon atom in the overall reaction [NiII-COCH3] + RS(H) ¡ú RSCOCH3 + NiII (+ H+) + 2e–. We have previously demonstrated these steps in Ni(II) complexes with physiol.-type ligation. In this work, it is shown that the reaction of acyl and thiolate ligands coordinated to Ni(I) affords thio esters in high yield. The complex [Ni(bpy)(CH3)2], established to be planar by an x-ray structure determination, reacts with 1 equiv of arenethiol to afford diamagnetic planar [Ni(bpy)(CH3)(SR)] (8) with R = p-C6H4CH3 (8a), 2,6-C6H3(CH3)2 (8b), mesityl (8c), 2,4,6-C6H2iPr3 (8d), and 2,6-C6H3Cl2 (8e) (bpy = 2,2′-bipyridyl). An analogous reaction gives [Ni(bpy)(C2H5)(S-mesityl)] (12) from [Ni(bpy)(C2H5)2]. Planar structures of 8c,e were confirmed by x-ray anal. Complexes 12 and 8 with different R substituents undergo thiolate ligand exchange in THF with Ke. Reaction of 8e with 1 equiv of carbon monoxide yields the acyl complex [Ni(bpy)(COCH3)(S-2,6-C6H3Cl2)] (9a), whose planar coordination unit was confirmed by x-ray methods. Treatment of the complexes 8 in THF with more than 3 equiv of carbon monoxide yields [Ni(bpy)(CO)2] and the thio esters RSCOCH3 in 96-100% yield in situ. A solution initially containing 8b and 12 gave under the same conditions four thio esters in equal amounts, consistent with four complexes in the equilibrated solution prior to reaction with carbon monoxide. Reaction of 9a in THF with carbon monoxide produced 2,6-dichlorophenyl thioacetate quant., indicating that Ni(II)-acyl-thiolate complexes are intermediates in thio ester formation. The overall reaction is [Ni(bpy)(R’)(SR)] + 3CO ¡ú RSCOR’ + [Ni(bpy)(CO)2] (R’ = CH3, C2H5); the two electrons in the generalized reaction are captured by the metal as Ni(0). A related and necessarily intramol. reaction of [Ni(bpy)(SCH2CH2CH2)] was confirmed and shown to produce ¦Ã-thiobutyrolactone in quant. yield in situ. Evidence supporting an analogous intramol. path for reaction systems based on 8 is summarized. This investigation provides the first examples of Ni-mediated acyclic thio ester synthesis and demonstrates a possible means of enzymic thio ester formation should CoA– and an acetyl group coordinate to the Ni(II) catalytic center.
Journal of the American Chemical Society published new progress about 22693-41-0. 22693-41-0 belongs to catalysis-chemistry, auxiliary class Other Functionalization Reagent, name is 2,4,6-Triisopropylbenzenethiol, and the molecular formula is C12H14BNO2, Computed Properties of 22693-41-0.
Referemce:
https://courses.lumenlearning.com/boundless-chemistry/chapter/catalysis/,
Catalysis – Wikipedia