CO binds at a cluster Fe that is bridged to the Ni. Methyl transfer to the Ni is then followed by attack on the bound CO, forming an acetyl adduct, which might migrate from Fe to Ni. Transfer of the acetyl group to CoA completes the catalytic cycle. Alkyl attack on metalbound CO is a well-precedented organometallic process that has been extensively studied (21). Usually the CO binds to the same...

The X-ray crystal structures of the methylcobalamin (MeCbl) analogues ethylcobalamin (EtCbl) and butylcobalamin (BuCbl) are reported. The X-ray crystal structures of EtCbl and BuCbl were obtained with some of the lowest crystallographic residuals ever achieved for cobalamins (R = 0.0468 and 0.0438, respectively). The Co-C bond distances for EtCbl and BuCbl are 2.023(2) and 2.028(4) A, whereas t...

Poly (vinylpyrrolidone)-grafted silica as an organic-inorganic hybrid material was used as an effective heterogeneous polymeric cosolvent catalyst in organic reactions. This modified silica catalyzed nucleophilic displacement of alkyl halides for easy preparation of alkyl thiocyanates, alkyl cyanides, alkyl azides and alkyl aryl ethers. Furthermore, the catalyst was applied for the conversion o...

SiO2-supported silyl chromate catalyst is an important industrial catalyst for production of high grade HDPE pipe materials. The control of the short chain branch (SCB) distribution using this catalyst system is still a great challenge. In this work, ethylene and 1-hexene copolymers were synthesized using SiO2-supported silyl chromate catalyst combined with triisobutylaluminium (TIBA), triethyl...

The synthesis of a range PBP supported palladium pincer complexes with different alkyl ligands is described. rates CO 2 insertion into the group are quantified and rationalized based on identity ligand.

Some early transition metal (Ti, V, Cr) complexes of the triphosphorus macrocycle 1,5,9-triethyl-1,5,9-triphosphacyclododecane, [12]aneP3Et3, and related derivatives [12]aneP3R3 (R = Ph, C3H6OMe) have been examined for their reactivity towards ethene and propene. All complexes of the type [12]aneP3Et3MCl3 display moderate catalytic activity in the homogeneous polymerisation of ethene when combi...

Several examples on Pd-catalysed carbonylation of methyl C(sp3)-H bonds with gaseous CO via Pd(II)/Pd(0) catalysis have been reported. However, methylene C(sp3)-H carbonylation remains a great challenge, largely due to the lack of reactivity of C-H bonds and the difficulty in CO migratory insertion. Herein, we report the stereoselective alkoxycarbonylation of both methyl and methylene C(sp3)-H ...

Various alkyl-(co-hydroxyalkyl) derivatives related to dibutylnitrosamine (DBN) were investigated for mutagenicity in the absence of liver-activation system. Butyl-(4-hydroxybutyl)-, butyl-(3-hydroxypropyl)-, and butyl-(2-hydroxyethyl)-nitrosamines were so tested and found to be mutagenic for TA 1535 strain of Salmonella typhimurium. In all cases, a simple dose--response relationship was observ...

We report the synthesis of a series of aryl- or alkyl-substituted 2-mercaptobenzothiazoles by direct thiolation of benzothiazoles with aryl or alkyl thiols via copper-mediated aerobic C-H bond activation in the presence of stoichiometric CuI, 2,2'-bipyridine and Na(2)CO(3). We also show that the approach can be extended to thiazole, benzimidazole, and indole substrates. In addition, we present ...

Separation of alkyl sulfate ethoxymers is investigated on various high-performance liquid chromatography (HPLC) stationary phases: Acclaim C18 Surfactant, Surfactant C8, and Hypercarb. For a fixed alkyl chain length, ethoxymers are eluted in the order of increasing number of ethoxylated units on Acclaim C18 Surfactant, whereas a reversed elution order is observed on Surfactant C8 and Hypercarb....