A Three-component Reaction of Phenol, Aldehyde, and Active Methylene Substrate under Lewis acid Catalysis: Successful Trapping of o-Quinone Methide to Afford Benzopyran Systems

Abstract

A three-component condensation involving reactive phenols, aldehydes, and active methylene substrates is described under BF3.Et2O catalysis to afford benzopyranyl products in satisfactory yields.

Aliphatic aldehydes in the synthesis of carbo- and heterocycles: Part II. Synthesis of six- and seven-membered rings, bicyclic compounds, and macrocycles

“…Mashraqui et al [144] were the first to report on the synthesis of fused pyran 132 from isobutyraldehyde (1e), β-naphthol (133) The Biginelli reaction discovered more than 115 years ago is now a good synthetic route to pyrimidines. The use of aliphatic aldehydes makes it possible to introduce an alkyl substituent into position 4 of pyrimidines 145 and 146 (Scheme 51).…”

An efficient one‐pot synthesis of 2‐aminopyrimidinomethylnaphtols under solvent‐free conditions

“…Multicomponent reactions (MCRs) have attracted considerable attention as they are performed without the need to isolate any intermediate during their processes . Because these MCRs are one‐pot processes in which three or more accessible components react to form a single product, the results of the MCRs can be achieved in a very fast, efficient, and time‐saving manner without isolation of any intermediate .…”

Guanidine Hydrochloride: A Highly Efficient Organocatalyst for the Synthesis of 12‐Aryl‐8,9,10,12‐tetrahydrobenzo[a]xanthene‐11‐ones Under Solvent‐Free Conditions

“…Thus, a broad utility range has made xanthenes prime synthetic candidates thereby accentuating the need to develop newer synthetic routes for scaffold manipulation of xanthene derivatives. Previously, tetrahydrobenzo[ a ]xanthenes have been synthesized under reflux for 4–5 h for long hours in dichloromethane or 1,2‐dichloroethane in the presence of acid catalysts such as Sr(OTf) 2 , InCl 3 or P 2 O 5 , pTSA in ionic liquid , 2,4,6‐trichloro‐1,3,5‐triazine , BF 3 .Et 2 O , tetrabutylammonium fluoride (TBAF) , and NaHSO 4 —SiO 2 .…”