ALKYLATION OF ACTIVE HYDROGEN COMPOUNDS WITH ALLYLIC AND BENZYLIC ALCOHOLS UNDER CoCl<sub>2</sub>CATALYSIS. A USEFUL SYNTHESIS OF GRIFOLIN
作者:J. Marquet、M. Moreno-Mañas
DOI:10.1246/cl.1981.173
日期:1981.2.5
COCl2 is a useful catalyst for the condensation of allylic and benzylic alcohols with active hydrogen compounds. Under these neutral conditions orcinol and farnesol react to afford the antibiotic grifolin.
An acid‐catalyzed regiodivergentannulation of biomass‐derived 4‐hydroxycoumarins with isoprene is developed, providing a facile access to pyranocoumarins and pyranochromones.
Isoprene: A Promising Coupling Partner in C–H Functionalizations
作者:Qing-An Chen、Wei-Song Zhang、Yan-Cheng Hu
DOI:10.1055/s-0040-1707172
日期:2020.10
basic industrial feedstock isoprene is an ideal alternative precursor. However, given that electronically unbiased isoprene might undergo six possible addition modes in the coupling reactions, it is difficult to control the selectivity. This article summarizes the strategies we have developed to achieve regioselective C–H functionalizations of isoprene under transition-metal and acid catalysis. 1 Introduction
Allylation/cyclization of β-ketolactone-type heterocyclic compounds, under In(OTf)3-catalysis, for the construction of biologically active dihydropyranocoumarin and dihydropyranochromone derivatives.
Abstract The chemoselective C- and O-prenylation of cyclic1,3-diketones was achieved by tuning the prenyl source and catalyst. In the presence of the solid acid Nafion, the coupling of 1,3-cyclohexanediones with isoprene gave C-prenylated 5-chromenones. Alternatively, using prenol as the substrate with the Lewis acid AlCl3 as the catalyst resulted in the exclusive O-prenylation of 1,3-cyclohexanediones