157968-59-7

Upstream product

• 95-56-7 2-hydroxybromobenzene 
• 127073-84-1 (R)-3-iodo-1-phenyl-1-propanol 
• 98-86-2 acetophenone 
• 254-04-6 2H-chromene 
• 93514-42-2 2-phenylchromene 
• 494-13-3 2-phenyl-4H-chromene 
• 100306-33-0 (1R)-3-chloro-1-phenylpropanol 
• 319924-80-6 (S)-1-bromo-2-(3-chloro-1-phenylpropoxy)-benzene 

Downstream Products

• 487-26-3 (2S)-flavanone 
• 20902-95-8 (2S,4R)-(+)-4-hydroxyflavan 
• 51196-83-9 (2S,4S)-(+)-cis-4-hydroxyflavan 

Relevant academic research and scientific papers

A stereocontrolled route to 2-substituted chromans

A two-step synthesis of 2-substituted chromans of high enantiomeric purity is described. Mitsunobu reaction of homochiral halopropanols 10 with 2-bromophenol (9), followed by treatment with n-butyllithium under Parham cycloalkylation conditions generates

Iridium-Catalyzed Asymmetric Hydroarylation of Chromene Derivatives with Aromatic Ketones: Enantioselective Synthesis of 2-Arylchromanes

Catalytic asymmetric hydroarylation of 2H-chromenes with aromatic ketones was realized by use of a cationic iridium/chiral phosphine complex. The reaction proceeded via olefin isomerization, followed by enantioselective hydroarylation, thus giving 2-arylchromanes in high yields with high enantioselectivity. (Figure presented.).

Ruthenium-NHC-catalyzed asymmetric hydrogenation of flavones and chromones: General access to enantiomerically enriched flavanones, flavanols, chromanones, and chromanols

Two to four! Readily available flavones and chromones were efficiently converted into four valuable chiral classes of O-heterocycles - flavanones, chromanones, flavanols, and chromanols - by means of an enantioselective Ru/NHC-catalyzed hydrogenation process (see scheme; NHC=N-heterocyclic carbene, PCC=pyridinium chlorochromate). Copyright

Enantioselective synthesis of chromanes by iridium-catalyzed asymmetric hydrogenation of 4H-chromenes

Iridium complexes of chiral oxazoline-based P,N-ligands proved to be efficient catalysts for the enantioselective hydrogenation of 2-aryl- and 2-alkyl-4H-chromenes. The best results were obtained with a ligand derived from threonine (ThrePHOX), which induced ee values of 95% to >99% in the hydrogenation of 2-methyl-, 2-cyclohexyl- and various 2-aryl-substituted chromenes. Georg Thieme Verlag Stuttgart.

Asymmetric dehydration of β-hydroxy esters and application to the syntheses of flavane derivatives

Catalytic asymmetric dehydration of β-aryl or alkyl substituted β-hydroxy esters via kinetic resolution has been investigated. A brief survey of 10 different chiral ligands is conducted to examine the effects of chiral ligand structure on selectivity of t

Inter- and intramolecular Mitsunobu reaction based approaches to 2-substituted chromans and chroman-4-ones

Two approaches to optically active 2-substituted chromans and chroman-4-ones are described. The first utilized an intermolecular Mitsunobu reaction of a homochiral halopropanol and 2-bromophenol followed by cyclization to the 2-substituted chroman. In addition, a double lithiation procedure was developed to introduce additional functionality to the chroman. The second approach utilized an intramolecular Mitsunobu cyclization to give the 2-substituted chroman-4-one nucleus. The methodologies were applied to the syntheses of several biologically active natural and synthetic products.