The Alkylation and Reduction of Heteroarenes with Alcohols Using Photoredox Catalyzed Hydrogen Atom Transfer via Chlorine Atom Generation
作者:Montserrat Zidan、Avery O. Morris、Terry McCallum、Louis Barriault
DOI:10.1002/ejoc.201900786
日期:2020.3.15
The alkylation of N‐heteroarenes using primary alcohols and ethers as radical precursors. The corresponding alkyl radical is formed via hydrogen atom transfer (HAT) process with a photoredox catalyzed chlorineatomgeneration as HAT agent. Furthermore, we explore the reduction of the heteroarenes when secondary alcohols are employed, giving moderate to high yields.
Proton spin-lattice relaxation-rates and nuclear Overhauser enhancement, in relation to the stereochemistry of β-d-mannopyranose 1,2-orthoacetates
作者:Photis Dais、Tony K.M. Shing、Arthur S. Perlin
DOI:10.1016/0008-6215(83)88341-4
日期:1983.10
Abstract Data are reported on spin-lattice relaxation-rates and nuclearOverhauserenhancement of protons of exo and endo diastereoisomers of 1,2-O-(1-methoxyethylidene) and 1,2-O-(1-benzyloxyethylidene) derivatives of 3,4,6-tri-O-acetyl-β- d -mannopyranose, and of some specifically deuterated analogs of these derivatives. The results verified assignments of the orientation at the quaternary carbon
Mechanistic Studies on CysS – A Vitamin B<sub>12</sub>-Dependent Radical SAM Methyltransferase Involved in the Biosynthesis of the <i>tert</i>-Butyl Group of Cystobactamid
作者:Yuanyou Wang、Tadhg P. Begley
DOI:10.1021/jacs.9b06454
日期:2020.6.3
Cobalamin (Cbl)-dependent radicalSAM methyltransferases catalyze methylation reactions at non-nucleophilic centers in a wide range of substrates. CysS is a Cbl-dependent radicalSAM methyltransferase involved in cystobactamid biosynthesis. This enzyme catalyzes the sequential methylation of a methoxy group to form ethoxy, i-propoxy, s-butoxy, and t-butoxy groups on a p-aminobenzoate peptidyl carrier
The structure of methyl fluoroformate from microwave spectroscopy and AB initio calculations
作者:P. Groner、C.L. Tolley、J.R. Durig
DOI:10.1016/0022-2860(90)80487-5
日期:1990.6
trans to fluorine). The s- cis conformation is not compatible with the experimental data as the data lead to an unrealistically large COC angle. The fully optimized structure from abinitiocalculations with the 6-31G* basis set which include electron correlation at the MP2 level is compared with the experimental structure and with earlier results from RHF/6-31G* calculations.