Kinetics and mechanism of the cleavage reactions of acylmanganese pentacarbonyl and methylmanganese pentacarbonyl

Manganese-Mediated C–C Bond Formation: Alkoxycarbonylation of Organoboranes

“…The reaction of an independently prepared sample of propionyl manganese pentacarbonyl with KO i Pr indeed produced the anticipated isopropyl propionate ester, as well as the reduced KMn(CO) 5 ( Figure S74 ). 33 …”

The role of phosphine in cobalt-catalyzed carbonylative polymerization of N-alkylaziridine

“…The electron-donating ability of the axial phosphine ligand in the trigonal bipyramidal complexes clearly exerts a consistent effect on both the stretching vibration of the equatorial CO and the stretching vibration of the C@O bond of the acetyl ligand. The latter event has important bearings to the carbonylative polymerization because an increase of back-donation from the Co d xz and d yz orbitals to the p* orbital of the acetyl C@O double bond not only weakens the C=O bond, but also strengths the acetyl-Co bond and thus retards its reactivity toward nucleophiles [62].…”

Zwitterionic Design Principle of Nickel(II) Catalysts for Carbonylative Polymerization of Cyclic Ethers

“…The proposition is in agreement with the anticipated reactivities of 4‐ vs. 5‐coordinate Ni + –acyl compounds, judging from the IR absorption wavenumber of the acyl C=O stretching vibration ( ν C=O ). A high ν C=O value similar to that of an organic ester or acyl chlorides indicates high electrophilicity and high reactivity, and a low ν C=O value similar to that of organic amide indicates the opposite . The reported ν C=O values of a pair of 4‐ and 5‐coordinate cationic Ni‐acetyl compounds are 1698 and 1733 cm −1 , respectively, indicating that the acetyl group of the 5‐coordinate compound is more electrophilic than that of the 4‐coordinate compound.…”

“…[24] Thereported n C=O values of apair of 4-and 5coordinate cationic Ni-acetyl compounds are 1698 and 1733 cm À1 , [25] respectively,i ndicating that the acetyl group of the 5-coordinate compound is more electrophilic than that of the 4-coordinate compound. Ther equire-ment of high CO pressure suggests that 5-coordinate species 1a+ CO is catalytically active,n ot 1a.T he proposition is in agreement with the anticipated reactivities of 4-vs.5coordinate Ni + -acyl compounds,judging from the IR absorption wavenumber of the acyl C=Ostretching vibration (n C=O ).…”