89-95-2Relevant articles and documents
Experimental and theoretical study of the effect of active-site constrained substrate motion on the magnitude of the observed intramolecular isotope effect for the P450 101 catalyzed benzylic hydroxylation of isomeric xylenes and 4,4'-dimethylbiphenyl
Audergon, Christian,Iyer, Krishna R.,Jones, Jeffrey P.,Darbyshire, John F.,Trager, William F.
, p. 41 - 47 (1999)
The validity of a cytochrome P450 (P450) 101 force field developed previously was tested by comparing to published results from other laboratories the predicted regioselectivity and stereoselectivity of both (R)- and (S)-norcamphor oxidation when the force field was used. Once validated, the force field was used to test the hypothesis that the magnitude of an observed intramolecular isotope effect is a function of the distance between equivalent but isotopically distinct intramolecular sites of oxidative attack. Molecular dynamics simulations and kinetic deuterium isotope effect experiments on benzylic hydroxylation were then conducted for a series of selectively deuterated isomeric xylenes and 4,4'-dimethylbiphenyl with P450 101. The molecular dynamics simulations predicted that the rank order of substrate mobility in the active site of P450 101 was o-xylene > p- xylene > dimethylbiphenyl. The observed isotope effects for the trideutero analogues were 10.6, 7.4, and 2.7, for the o-xylene, p-xylene, and 4,4'- dimethylbiphenyl, respectively. Thus, as the theoretically predicted rates of interchange between the isotopically distinct methyl groups decrease, the observed isotope effect decreases. The agreement between the theoretical predictions and experimental results provides strong support for the distance hypothesis stated above and for the potential of computational analysis to enhance our understanding of protein/small molecule interactions.
CeO2-nanocubes as efficient and selective catalysts for the hydroboration of carbonyl groups
Bhawar, Ramesh,Bose, Shubhankar Kumar,Patil, Kiran S.
supporting information, p. 15028 - 15034 (2021/09/04)
The CeO2-nanoparticle catalysed hydroboration of carbonyl compounds with HBpin (pin = OCMe2CMe2O) is reported to afford the corresponding borate esters in excellent yield. A series of aromatic and aliphatic aldehydes and ketones having synthetically important functional groups were well-Tolerated under mild reaction conditions. Further, chemoselective hydroboration of aldehydes over other reducible functional groups such as ketone, nitrile, hydroxide, alkene, alkyne, amide, ester, nitro, and halides was achieved. Importantly the catalyst can be recycled up to ten runs with slight loss in activity. This journal is
Reaction of Diisobutylaluminum Borohydride, a Binary Hydride, with Selected Organic Compounds Containing Representative Functional Groups
Amberchan, Gabriella,Snelling, Rachel A.,Moya, Enrique,Landi, Madison,Lutz, Kyle,Gatihi, Roxanne,Singaram, Bakthan
supporting information, p. 6207 - 6227 (2021/05/06)
The binary hydride, diisobutylaluminum borohydride [(iBu)2AlBH4], synthesized from diisobutylaluminum hydride (DIBAL) and borane dimethyl sulfide (BMS) has shown great potential in reducing a variety of organic functional groups. This unique binary hydride, (iBu)2AlBH4, is readily synthesized, versatile, and simple to use. Aldehydes, ketones, esters, and epoxides are reduced very fast to the corresponding alcohols in essentially quantitative yields. This binary hydride can reduce tertiary amides rapidly to the corresponding amines at 25 °C in an efficient manner. Furthermore, nitriles are converted into the corresponding amines in essentially quantitative yields. These reactions occur under ambient conditions and are completed in an hour or less. The reduction products are isolated through a simple acid-base extraction and without the use of column chromatography. Further investigation showed that (iBu)2AlBH4 has the potential to be a selective hydride donor as shown through a series of competitive reactions. Similarities and differences between (iBu)2AlBH4, DIBAL, and BMS are discussed.
Direct Heterogenization of the Ru-Macho Catalyst for the Chemoselective Hydrogenation of α,β-Unsaturated Carbonyl Compounds
Padmanaban, Sudakar,Gunasekar, Gunniya Hariyanandam,Yoon, Sungho
supporting information, p. 6881 - 6888 (2021/03/01)
In this study, a commercially available homogeneous pincer-type complex, Ru-Macho, was directly heterogenized via the Lewis acid-catalyzed Friedel-Crafts reaction using dichloromethane as the cross-linker to obtain a heterogeneous, pincer-type Ru porous organometallic polymer (Ru-Macho-POMP) with a high surface area. Notably, Ru-Macho-POMP was demonstrated to be an efficient heterogeneous catalyst for the chemoselective hydrogenation of α,β-unsaturated carbonyl compounds to their corresponding allylic alcohols using cinnamaldehyde as a model compound. The Ru-Macho-POMP catalyst showed a high turnover frequency (TOF = 920 h-1) and a high turnover number (TON = 2750), with high chemoselectivity (99%) and recyclability during the selective hydrogenation of α,β-unsaturated carbonyl compounds.
