78239-09-5

Upstream product

• 5392-10-9 2-bromo-4,5-dimethoxybenzaldehyde 
• 59142-61-9 2-benzoyl-4, 5-dimethoxyl-1-bromobenzene 
• 100-58-3 phenylmagnesium bromide 
• 59142-62-0 (2-bromo-4,5-dimethoxyphenyl)phenylmethanol 
• 98-88-4 benzoyl chloride 
• 4038-14-6 3,4-dimethoxybenzophenone 
• 91-16-7 1,2-dimethoxybenzene 
• 66284-45-5 (3,4-dimethoxyphenyl)diphenylmethanol 

Downstream Products

• 119-61-9 benzophenone 
• 1569315-67-8 2,3,8,9-tetramethoxy-6,6-diphenyl-6H-benzo[c]chromene 

Relevant academic research and scientific papers

Substitution controlled functionalization of ortho -bromobenzylic alcohols via palladium catalysis: Synthesis of chromenes and indenols

An efficient domino Pd-catalyzed transformation of simple ortho-bromobenzyl tertiary alcohols to chromenes is presented. Their formation is believed to proceed via the formation of a five-membered palladacycle, which, in turn, involves in an intermolecular homocoupling with the second ortho- bromobenzyltertiary alcohol to yield the homo-biaryl bond followed by intramolecular C-O bond formation. Interestingly, when there is an allylic substituent on the benzylic carbon atom, a chemoselective switch was observed, which preferred intramolecular Heck coupling and gave indenols. Further, it has been confirmed that the tertiary alcohol functionality is indispensible to give the coupled products, whereas the use of primary/secondary benzylic alcohols furnished the simple carbonyl products via a possible reductive debromination followed by oxidation due to the availability of β-hydrogen(s).

Anomalous Acetoxylation of Aromatic Nuclei: Some Structural Requirements in the Substrate

For certain aromatic nuclei, bromination in acetic acid in the presence of pyridine is accompanied by nuclear acetoxylation.As first observed with galbulin, when two alkoxyl groups, one meta and one para to a benzylic centre of the substrate are present, acetoxylation occurs at the intervening ortho position.Under the given conditions, acetoxylation occurs at position 8 of 6,7-dimethoxy-1-phenyl-1,2,3,4-tetrahydronaphthalene, and at position 2 of 3,4-dimethoxy diphenyl and triphenyl-methanes.Acetoxylation does not occur in the absence of either of the alkoxy groups or in the absence of pyridine, not does it occur in the pendant ring of 1-(3',4'-dimethoxyphenyl)-1,2,3,4-tetrahydronaphthalene.These results are consistent with the earlier suggestion that the reaction occurs by way of initial oxidative formation of a doubly benzylic cation