Cu-Catalyzed Reaction of 1,2-Dihalobenzenes with 1,3-Cyclohexanediones for the Synthesis of 3,4-Dihydrodibenzo[b,d]furan-1(2H)-ones

Publication Type

Journal contribution (peer reviewed)

Authors

Aljaar, N.; Malakar, C. C.; Conrad, J.; Strobel, S.; Schleid, T.; Beifuss, U.

Year of publication

2012

Published in

J. Org. Chem.

Band/Volume

77/

DOI

10.1021/jo3014275

Page (from - to)

7793-7803

The Cu(I)-catalyzed reaction of 1-bromo-2-iodobenzenes and other 1,2-dihalobenzenes with 1,3-cyclohexanediones in DMF at 130 °C using Cs₂CO₃ as a base and pivalic acid as an additive selectively delivers 3,4-dihydrodibenzo[b,d]furan-1(2H)-ones with yields ranging from 47 to 83%. The highly regioselective domino process is based on an intermolecular Ullmann type C-arylation followed by an intramolecular Ullmann type O-arylation. Substituted products are accessible by employing substituted 1-bromo-2-iodobenzenes and substituted 1,3-cyclohexanediones as substrates. Reaction with an acyclic 1,3-diketone yields the corresponding benzo[b]furan.