80427-39-0Relevant academic research and scientific papers
NHC-Organocatalyzed CAr?O Bond Cleavage: Mild Access to 2-Hydroxybenzophenones
Janssen-Müller, Daniel,Singha, Santanu,Lied, Fabian,Gottschalk, Karin,Glorius, Frank
, p. 6276 - 6279 (2017/05/19)
A Truce–Smiles rearrangement of acyl-anion equivalents generated by N-heterocyclic carbene (NHC) catalysis has been achieved. The developed method includes CAr?O, CAr?S, or CAr?N bond cleavage for the formation of a CAr?C bond and enables access to 2-hydroxybenzophenones, an important structural motif that is present in several bioactive natural products. By utilizing this procedure, the alkaloid taxilamine was synthesized in three steps. DFT calculations and control experiments support a classical SNAr mechanism with a catalyst-bound Meisenheimer-type intermediate. The method features mild reaction conditions, excellent functional-group tolerance, and a broad substrate scope, including various classes of (hetero)arenes.
Studies on the Friedel-Crafts Reaction. XVI, Preparation of Isomeric 2-Acyl- and 3-Acyl-4-methoxy Phenols
Martin, Robert
, p. 1155 - 1164 (2007/10/02)
Acylation of 4-methoxy phenol according to Friedel and Crafts, as well as the rearrangement of its esters according to Fries lead always to 2-acyl-4-methoxy phenols or to their demethylated compounds.The unknown 3-acyl-4-methoxyphenols were prepared in two steps: First, the ester is acylated with the corresponding acyl chloride and SnCl4 in nitromethane.In the second step the resulting ketoesters are hydrolysed.This is a general method.The yields of meta-acylphenols are between 40 and 90percent.The isomeric 2-acyl-4-methoxyphenols which were partly unknown or accessible only in low yields have also been prepared for comparative spectral studies (UV, IR, NMR, MS) of ortho- and meta-acylphenols. - Keywords: Friedel-Crafts acylation; Fries rearrangement; Ketoesters; Spectral data
