Direct C–C Bond Formation from Alkanes Using Ni-Photoredox Catalysis
作者:Laura K. G. Ackerman、Jesus I. Martinez Alvarado、Abigail G. Doyle
DOI:10.1021/jacs.8b09191
日期:2018.10.31
C(sp3)-H bonds and chloroformates has been accomplished via nickel and photoredox catalysis. A diverse range of feedstock chemicals, such as (a)cyclic alkanes and toluenes, along with late-stage intermediates, undergo intermolecular C-C bond formation to afford esters under mild conditions using only 3 equiv of the C-H partner. Site selectivity is predictable according to bond strength and polarity
to afford triflyl-substituted amines in moderate to high yields. Marked selectivity for tertiary over secondary C–H bonds was observed; primary (methyl) C–H bonds were inert. Addition of hexafluoroisopropanol to inhibit decomposition of 1 dramatically improved the C–H amination efficiencies. Second-order kinetics, activation parameters (negative activation entropy), deuterium isotope effects, and theoretical
accomplished an efficient and mild multiple deuteration method for alkanescatalyzed by the combined use of heterogeneous platinum on carbon (Pt/C) and rhodium on carbon (Rh/C) catalysts in i-PrOD-d8 and D2O as a mixed solvent. The present multi-deuteration could be initiated by the transition metal-catalyzed dedeuteration of i-PrOD-d8 to produce D2 and the subsequent C–H bond activation of alkanes catalyzed
我们已经在i -PrOD- d 8和D 2 O中将异质碳载铂(Pt / C)和铑碳载(Rh / C)催化剂组合使用,实现了一种高效,温和的多重氘烷烃催化方法。混合溶剂。当前的多重氘化可以通过过渡金属催化的i -PrOD- d 8的氘化反应产生D 2以及随后的由Pt / C和/或Rh / C-D催化的烷烃的C–H键活化而引发。2复杂。该方法可用于在温和条件下将多种线性,支链和环状烷烃作为有用的氘代物质进行氘化。
CIRCULAR ECONOMY METHODS OF PREPARING UNSATURATED COMPOUNDS
申请人:INTERNATIONAL FLAVORS & FRAGRANCES INC.
公开号:US20170362155A1
公开(公告)日:2017-12-21
Methods of preparing unsaturated compounds or analogs through dehydrogenation of corresponding saturated compounds and/or hydrogenation of aromatic compounds are disclosed.
通过脱氢饱和化合物和/或芳香化合物氢化的方法制备不饱和化合物或类似物已被披露。
The chemistry of thiophene-based bis-(p-quinodimethanes): an approach to macrocycles
作者:Walter S. Trahanovsky、Douglas A. Klumpp
DOI:10.1016/j.tetlet.2016.04.062
日期:2016.6
Bis-2,5-dimethylene-2,5-dihydrothiophenes have been generated in the gas-phase by flash vacuum pyrolysis (FVP) of diester precursors. These thiophene-based bis-(p-quinodimethanes) are shown to undergo reactions leading to macrocycles. The conversions are consistent with a mechanism involving cyclic diradical intermediates followed by disproportionation of the radical centers.