928-80-3Relevant articles and documents
CYP505E3: A Novel Self-Sufficient ω-7 In-Chain Hydroxylase
Maseme, Mpeyake Jacob,Opperman, Diederik Johannes,Pennec, Alizé,Smit, Martha Sophia,van Marwijk, Jacqueline
supporting information, p. 10359 - 10362 (2020/04/23)
The self-sufficient cytochrome P450 monooxygenase CYP505E3 from Aspergillus terreus catalyzes the regioselective in-chain hydroxylation of alkanes, fatty alcohols, and fatty acids at the ω-7 position. It is the first reported P450 to give regioselective in-chain ω-7 hydroxylation of C10–C16 n-alkanes, thereby enabling the one step biocatalytic synthesis of rare alcohols such as 5-dodecanol and 7-tetradecanol. It shows more than 70 percent regioselectivity for the eighth carbon from one methyl terminus, and displays remarkably high activity towards decane (TTN≈8000) and dodecane (TTN≈2000). CYP505E3 can be used to synthesize the high-value flavour compound δ-dodecalactone via two routes: 1) conversion of dodecanoic acid into 5-hydroxydodecanoic acid (24 percent regioselectivity), which at low pH lactonises to δ-dodecalactone, and 2) conversion of 1-dodecanol into 1,5-dodecanediol (55 percent regioselectivity), which can be converted into δ-dodecalactone by horse liver alcohol dehydrogenase.
Additive-Free Isomerization of Allylic Alcohols to Ketones with a Cobalt PNP Pincer Catalyst
Spiegelberg, Brian,Dell'Acqua, Andrea,Xia, Tian,Spannenberg, Anke,Tin, Sergey,Hinze, Sandra,de Vries, Johannes G.
supporting information, p. 7820 - 7825 (2019/05/22)
Catalytic isomerization of allylic alcohols in ethanol as a green solvent was achieved by using air and moisture stable cobalt (II) complexes in the absence of any additives. Under mild conditions, the cobalt PNP pincer complex substituted with phenyl groups on the phosphorus atoms appeared to be the most active. High rates were obtained at 120 °C, even though the addition of one equivalent of base increases the speed of the reaction drastically. Although some evidence was obtained supporting a dehydrogenation–hydrogenation mechanism, it was proven that this is not the major mechanism. Instead, the cobalt hydride complex formed by dehydrogenation of ethanol is capable of double-bond isomerization through alkene insertion–elimination.
Synthesis, structural characterization and C–H activation property of a tetra-iron(III) cluster
Dey, Dhananjay,Patra, Moumita,Al-Hunaiti, Afnan,Yadav, Hare Ram,Al-mherat, Afrah,Arar, Sharif,Maji, Milan,Choudhury, Angshuman Roy,Biswas, Bhaskar
, p. 220 - 226 (2019/01/05)
A non-heme tetra-iron cluster, [Fe4 III(μ-O)2(μ-OAc)6(2,2′-bpy)2(H2O)2](NO3 ?)(OH?) (1), [OAc = acetate; 2,2′-bpy = 2,2′-bipyridine] containing oxido- and acetato-bridges was synthesized and structurally characterized by different spectroscopic methods including single crystal X-ray diffraction studies. X-ray crystal structure analysis of 1 revealed that tetra-iron complex was crystallized in monoclinic system with C2/c space group. Each of the Fe centres in 1 was found to exist in octahedral geometry and interconnected by oxido- and acetato-bridges. Bond valence sum (BVS) calculation recommended the existence of iron centres in +3 oxidation state. Variable temperature magnetic measurement authenticated the dominating antiferromagnetic ordering among the iron centres in the solid state of 1. This tetra-iron cluster was also evaluated as an efficient catalytic system towards the oxidation of both linear & cyclic alkanes without production of primary C–H bond oxidation products. Oxidation of secondary C–H bonds attested the formation of both the corresponding alcohols & ketones in 27–900 TONs. The tetra-iron catalytic system with Alcohol/Ketone values 0.2–1.7 indicated the involvement of freely diffusing carbon-centered radicals rather than metal based oxidant.
