Copper-catalyzed [1,2]-rearrangements of allylic iodides and aryl α-diazoacetates
作者:Bin Xu、Jackson A. Gartman、Uttam K. Tambar
DOI:10.1016/j.tet.2017.01.048
日期:2017.7
iodonium ylides are synthetically useful reactions for the generation of functionalized α-iodoesters. Allylic iodides are coupled with α-diazoesters in the presence of a copper catalyst and a ligand to generate iodonium ylides, which undergo metal-mediated rearrangements. By fine-tuning the structure of the ligand, we have reversed the regioselectivity of copper-catalyzed reactions of iodonium ylides from
Synthesis of 1,3-Substituted Cyclobutanes by Allenoate-Alkene [2 + 2] Cycloaddition
作者:Michael L. Conner、M. Kevin Brown
DOI:10.1021/acs.joc.6b01446
日期:2016.9.2
A method for the [2 + 2] cycloaddition of terminal alkenes with allenoates is presented. This process allows for the rapid synthesis of 1,3-substituted cyclobutanes in high yield under simple and robust reaction conditions.
enables the expedient construction of a host of β-fluoroalkyl-containing cinnamate derivatives. The reaction proceeds through visible-light-promoted gold redox catalysis, occurs smoothly under very mild reaction conditions, accommodates a large variety of functional groups, and more importantly allows the incorporation of fluorine and aryl groups with excellent regio- and stereoselectivity. The concomitant
chemically selective detection of natural nucleobase modifications has been regarded as the key step in understanding their important roles in epigenetics. Herein, for the first time, we introduce a Wittig reaction into the design of reaction-based fluorescent probes for ratiometrically detecting 5fU, selectively labelling 5fU-modified DNA and imaging intracellular 5fU produced by γ-irradiation.