Synthetic connections to the aromatic directed metalationreaction. Unsymmetrical biaryls by palladium-catalyzed cross coupling of directed metalation-derived arylboronic acids with aryl halides
作者:M.J. Sharp、V. Snieckus
DOI:10.1016/s0040-4039(00)95108-6
日期:1985.1
The arylboronic acids 2 and 4 derived by directed ortho metalation of benzamides and carbamates, undergo an efficient palladium-catalyzed cross coupling reaction with a variety of arylhalides to yield unsymmetrical biaryls and heterobiaryls (Table).
ALO, B. I.;KANDIL, A.;PATIL, P. A.;SHARP, M. J.;SIDDIGUI, M. A.;SNIECKUS,+, J. ORG. CHEM., 56,(1991) N2, C. 3763-3768
作者:ALO, B. I.、KANDIL, A.、PATIL, P. A.、SHARP, M. J.、SIDDIGUI, M. A.、SNIECKUS,+
DOI:——
日期:——
SHARP, M. J.;SNIECKUS, V., TETRAHEDRON LETT., 1985, 26, N 49, 5997-6000
作者:SHARP, M. J.、SNIECKUS, V.
DOI:——
日期:——
Sequential directed ortho metalation-boronic acid cross-coupling reactions. A general regiospecific route to oxygenated dibenzo[b,d]pyran-6-ones related to ellagic acid
作者:B. I. Alo、A. Kandil、P. A. Patil、M. J. Sharp、M. A. Siddiqui、Victor Snieckus、P. D. Josephy
DOI:10.1021/jo00012a004
日期:1991.6
A general regiospecific synthesis of dibenzo[b,d]pyran-6-one derivatives 1a,c and 8a-i related to ellagic acid is described (Scheme I, Table I). The sequence involves directed ortho metalation-boronation of benzamides 4 to give the arylboronic acids 5, which, upon palladium-catalyzed cross-coupling with alkoxybromobenzenes 6 leads to the biphenylamides 7. BBr3 demethylation followed by acid-catalyzed cyclization affords pyranone 8. In this manner, the naturally occurring dibenzopyranones 1a, autumnariol (1c), and the heterocyclic analogue 13 (Scheme III) were efficiently prepared.