6005-12-5

Upstream product

• 4805-75-8 3-bromo-2,2-diphenyl-chroman-4-one 
• 1072-85-1 o-fluorobromobenzene 
• 451-40-1 phenyl benzyl ketone 
• 201230-82-2 carbon monoxide 
• 2491-31-8 2-hydroxy-deoxybenzoin 
• 100-44-7 benzyl chloride 
• 501-65-5 diphenyl acetylene 
• 108-95-2 phenol 
• 90-02-8 salicylaldehyde 
• 3780-21-0 2,2-diphenylchroman-4-one 
• 74719-09-8 2-(2-phenylacetyl)phenyl benzoate 
• 118-55-8 phenyl Salicylate 
• 10268-61-8 4-methoxyphenyl 2-hydroxybenzoate 
• 69-72-7 salicylic acid 

Downstream Products

• 855744-33-1 2,3-diphenyl-chromene-4-thione 

Relevant academic research and scientific papers

Iridium-Catalyzed and Ligand-Controlled Carbonylative Synthesis of Flavones from Simple Phenols and Internal Alkynes

Flavones are important natural products with diverse biological activities. In this study, a novel procedure for the carbonylative synthesis of flavones has been developed by using simple phenols and internal alkynes as the substrates. Various flavones were isolated in moderate to good yields with excellent regioselectivity and functional group tolerance by using an iridium catalyst system. Notably, this is the first example of direct carbonylative annulation of non-preactivated phenols and alkynes to produce flavones, with the choice of ligand proving to be critical for the success of this transformation.

Nickel-catalyzed CO/OH annulation of salicylate esters with alkynes: Activation of CO bond in Esters

The Ni-catalyzed CO/OH annulation of salicylate esters with alkynes, leading to the production of chromone derivatives is reported. The key step in the reaction is the cleavage of an acyl CO bond. The presence of a base is essential for the reaction to proceed.

Nickel-catalyzed C-O/N-H, C-S/N-H, and C-CN/N-H annulation of aromatic amides with alkynes: C-O, C-S, and C-CN activation

The Ni-catalyzed reaction ofortho-phenoxy-substituted aromatic amides with alkynes in the presence of LiOtBu as a base results in C-O/N-H annulation with the formation of 1(2H)-isoquinolinones. The use of a base is essential for the reaction to proceed. The reaction proceeds, even in the absence of a ligand, and under mild reaction conditions (40 °C). An electron-donating group on the aromatic ring facilitates the reaction. The reaction was also applicable to carbamate (C-O bond activation), methylthio (C-S bond activation), and cyano (C-CN bond activation) groups as leaving groups.

Iridium-Catalyzed Aerobic Coupling of Salicylaldehydes with Alkynes: A Remarkable Switch of Oxacyclic Product

The iridium(III)/copper(II)-catalyzed dehydrogenative coupling of salicylaldehydes with internal alkynes proceeds efficiently under atmospheric oxygen through aldehyde C?H bond cleavage and decarbonylation. A variety of benzofuran derivatives can be synthesized by the environmentally benign procedure. DFT calculations suggest that this unique transformation involves the facile deinsertion of CO in the key metallacycle intermediate, which is in marked contrast to the corresponding rhodium(III) catalysis that leads to CO-retentive chromone derivatives.

One-Pot Domino Friedel-Crafts Acylation/Annulation between Alkynes and 2-Methoxybenzoyl Chlorides: Synthesis of 2,3-Disubstituted Chromen-4-one Derivatives

A highly regioselective synthesis of 2,3-disubstituted chromen-4-one derivatives is accomplished from readily available internal alkynes and 2-methoxybenzoyl chlorides. The reaction proceeds via a domino intermolecular Friedel-Crafts acylation/intramolecular vinyl carbocation trapping (or oxa-Michael addition)/demethylation reaction sequence. This Lewis acid promoted method features relatively mild reaction conditions to synthesize a variety of 2,3-disubstituted chromen-4-one derivatives in one pot with up to 93% yield. The chromen-2-one (coumarin) product was obtained when 2,6-dimethoxybenzoyl chloride was used as a starting material via an electrophilic aromatic substitution/rearrangement process.

Unified Approach to (Thio)chromenones via One-Pot Friedel-Crafts Acylation/Cyclization: Distinctive Mechanistic Pathways of β-Chlorovinyl Ketones

A facile synthetic method to chromenones and thiochromenones has been developed using a one-pot Friedel-Crafts acylation of alkynes with suitably substituted benzoyl chlorides. This unified approach to (thio)chromenones is readily applicable to aryl- and alkylalkynes where the stereochemically well-defined β-chlorovinyl ketone intermediates undergo distinctively different cyclization pathways. The ready availability of both starting materials, alkynes and benzoyl chlorides, coupled with the experimental simplicity makes the current synthetic method to (thio)chromenones fast, efficient, and practical.

C-H Functionalization via Remote Hydride Elimination: Palladium Catalyzed Dehydrogenation of ortho-Acyl Phenols to Flavonoids

Although deprotonation of electron-poor C-H bonds to carbon anions with bases has long been known and widely used in organic synthesis, the hydride elimination from electron-rich C-H bonds to carbon cations or partial carbocations for the introduction of nucleophiles is a comparatively less explored area. Here we report that the carbonyl β-C(sp3)-H bond hydrogens of ortho-acyl phenols could be substituted by intramolecular phenolic hydroxyls to form O-heterocycles, followed by dehydrogenation of the O-heterocycle into flavonoids. The cascade reaction is catalyzed by Pd/C without added oxidants and sacrificing hydrogen acceptors.

Palladium-Catalyzed Carbonylative Synthesis of 2,3-Disubstituted Chromones

An unexpected palladium-catalyzed carbonylative synthesis of 2,3-disubstituted chromones has been developed. Starting from 2-bromofluorobenzenes and ketones, the corresponding chromones were produced in good yields. By control experiments, this transformation was found to proceed through a sequential carbonylation/Claisen-Hasse rearrangement/intramolecular nucleophilic aromatic substitution approach (SNAr). More specifically, the reaction sequence started with a palladium-catalyzed carbonylation of the ketone with o-bromofluorobenzene to give the vinyl benzoates, which subsequently transformed into 1,3-diketones via a Claisen-Hasse rearrangement. The final products were produced after an intramolecular SNAr reaction of the in situ formed 1,3-diketone.

Ru(II)-catalyzed C-H activation and annulation of salicylaldehydes with monosubstituted and disubstituted alkynes

The Ru(ii)-catalyzed C-H activation and annulation reaction of salicylaldehydes and disubstituted alkynes affords chromones in high yields. This reaction also works with terminal alkynes and tolerates a wide range of sensitive functional groups. The selectivity pattern of this Ru(ii)-catalyzed annulation reaction is different from the known Au(i), Rh(iii)-catalyzed annulation reactions of salicylaldehydes and terminal alkynes.