We developed a one-pot method for the generation of benzynes from a range of readily available 2-hydroxyphenylboronic acids. This method features the in situ activation of both boronic acid and hydroxyl groups of the substrate to enhance benzyne generation at 60 °C. Such mild conditions facilitate the generation of functionalized benzynes that immediately react with diverse arynophiles to produce multisubstituted
Cross Coupling of Bromo Sydnones: Development of a Flexible Route toward Functionalized Pyrazoles
作者:Duncan L. Browne、John B. Taylor、Andrew Plant、Joseph P. A. Harrity
DOI:10.1021/jo802240e
日期:2009.1.2
The application of a Suzuki cross coupling approach to a range of C-4 substituted sydnones from a 4-bromosydnone is described. Moreover, the potential of this approach to prepare a diverse range of pyrazoles is demonstrated.
by sequential benzyne generation and reaction with arynophiles. The key features of this method include the chemoselective generation of two triple bonds in a single benzene ring under fluoride-mediated mild conditions, and the regiocontrol of each benzynereaction by the substituent next to the triple bond. This method produced various benzo-fused heteroaromatic compounds via reactions with arynophiles
Stable 2-(trimethylsilyl)phenyl trimethylsilyl ethers, readily obtained from the corresponding halogenated phenols in two steps, were identified as novel benzyne precursors. These species were converted to benzynes by a domino reaction of O-desilylation, O-nonaflylation, and β-elimination under mild conditions using nonafluorobutanesulfonyl fluoride (NfF) and tetrabutylammonium triphenyldifluorosilicate