Focused
<i>ortho</i>
‐Lithiation and Functionalization of
<i>p</i>
‐Bromo‐ and
<i>p</i>
‐Iodoanisole
作者:D. W. Slocum、John A. Jennings、Thomas K. Reinscheld、Paul E. Whitley
DOI:10.1002/ejoc.201800616
日期:2018.8.31
By use of the strategy of ortho‐lithiation, p‐bromoanisole and p‐iodoanisole were ortho‐metalated using ortho‐lithiodimethylbenzylamine as the metalating agent. No halogen exchange was noted during these same conditions. These studies add to the emerging evidence of a hitherto unidentified acidifying effect on the proton(s) ortho‐ to a directing metalation group by both a p‐iodo and a p‐bromo substituent
Metalations utilizing aryllithiums; ortho-functionalization of p-bromoanisole (pBrA)
作者:D.W. Slocum、Troy L. Reece、Rebecca D. Sandlin、Thomas K. Reinscheld、Paul E. Whitley
DOI:10.1016/j.tetlet.2009.01.104
日期:2009.4
An ortho-metalation protocol has been developed, which permits the survival of a bromine substituent in p-bromoanisole. Eight derivatives of the generated ortho-lithiated intermediate have been prepared. A neglected metalation concept is being explored here: one which proposes that minimizing the pK(a) difference between the aryl substrate and the conjugate acid of the metalating agent will lead to a regiospecific and selective metalation process. Published by Elsevier Ltd.