Fused-Ring Formation by an Intramolecular “Cut-and-Sew” Reaction between Cyclobutanones and Alkynes
作者:Lin Deng、Likun Jin、Guangbin Dong
DOI:10.1002/anie.201712487
日期:2018.3.1
alkynes to construct cyclohexenone‐fused rings is described herein. The challenge arises from the need for selective coupling at the more sterically hindered proximal position, and can be addressed by using an electron‐rich, but less bulky, phosphine ligand. The control experiment and 13C‐labelling study suggest that the reaction may start with cleavage of the less hindered distal C−C bond of cyclobutanones
Herein we describe the development of a highly selective kinetic resolution of cyclobutanonesvia a Rh-catalyzed "cut-and-sew" reaction with selectivity factor up to 785. This reaction takes place at room temperature with excellent efficiency. Various trans 5,6-fused bicycles and C2-substituted cyclobutanones were obtained with excellent ee, which can be further used as chiral building blocks. DFT
在此,我们描述了通过 Rh 催化的“切割和缝合”反应对环丁酮进行高选择性动力学拆分的发展,选择性因子高达 785。该反应在室温下以优异的效率进行。获得了各种具有优异 ee 的反式 5,6-稠合双环和 C2-取代的环丁酮,可进一步用作手性构件。DFT 计算揭示了 DTBM-segphos 配体在通过有利的配体-底物分散相互作用稳定决定 CC 氧化加成过渡态的速率和对映选择性方面的关键作用。
Conformational restriction of methionyl tRNA synthetase inhibitors leading to analogues with potent inhibition and excellent gram-Positive antibacterial activity
作者:Richard L. Jarvest、John M. Berge、Pamela Brown、Catherine S.V. Houge-Frydrych、Peter J. O'Hanlon、David J. McNair、Andrew J. Pope、Stephen Rittenhouse
DOI:10.1016/s0960-894x(03)00093-3
日期:2003.4
Conformationally restricted analogues of the central linker unit of bacterial methionyl tRNA synthetase (MRS) inhibitors have been prepared. The (IS,2R)-cyclopentylmethyl moiety was identified as the preferred cyclic linker, with significant diastereo- and enantio selectivity of activity. Combination of this linker with an optimal substituted aryl right-hand side has resulted in a compound with exceptionally good antibacterial activity against staphylococci and enterococci, including antibiotic resistant strains. (C) 2003 Elsevier Science Ltd. All rights reserved.