10.1021/jo0620359.s001
Manlio Alessi
Manlio
Alessi
Andrew L. Larkin
Andrew L.
Larkin
Kevin A. Ogilvie
Kevin A.
Ogilvie
Laine A. Green
Laine A.
Green
Sunny Lai
Sunny
Lai
Simon Lopez
Simon
Lopez
Victor Snieckus
Victor
Snieckus
Directed <i>ortho</i> Metalation−Boronation and Suzuki−Miyaura Cross
Coupling of Pyridine Derivatives: A One-Pot Protocol to
Substituted Azabiaryls<sup>#</sup>
American Chemical Society
2007
sequence
Scheme
pyridyl boronates
metalation protocol
method
synthesis
ortho metalation
pyridyl boronic acids
azabiaryls 19
isomeric pyridyl carboxamides 15
procedure
2007-03-02 00:00:00
Journal contribution
https://acs.figshare.com/articles/journal_contribution/Directed_i_ortho_i_Metalation_Boronation_and_Suzuki_Miyaura_Cross_Coupling_of_Pyridine_Derivatives_A_One_Pot_Protocol_to_Substituted_Azabiaryls_sup_sup_/3020752
A general method for the synthesis of azabiaryls <b>19a</b>−<b>t</b> by a one-pot procedure involving a Directed
<i>ortho</i> metalation (D<i>o</i>M)−boronation−Suzuki−Miyaura cross coupling sequence is described. Aside from
the three isomeric pyridyl carboxamides <b>15a</b>−<b>c</b>, chloro-, fluoro-, and <i>O</i>-carbamoyl pyridines are adapted
to this method providing a range of azabiaryls (Table ). The method has an advantage in that it avoids
the recognized difficult isolation of pyridyl boronic acids and their instability toward deboronation. The
efficient synthesis of hydroxypicolinamides <b>12</b>−<b>14</b> (Scheme ) by a one-pot metalation−boronation−oxidation sequence with the LDA-B(O<i><sup>i</sup></i><sup></sup>Pr)<sub>3</sub> <i>in situ</i> procedure that avoids self-condensation of incipient
<i>ortho</i>-metalated species (Scheme ) is delineated. The conversion of azabiaryls <b>19b</b>,<b>e</b>,<b>h</b>,<b><i>l</i></b> into azafluorenones <b>20b</b>,<b>e</b>,<b>h</b>,<b><i>l</i></b> by a directed remote metalation protocol is demonstrated (Table ). A comprehensive
survey of pyridyl boronates, of considerable interest in contemporary heterocyclic synthetic chemistry,
is given (Figure ).