Bromine–lithium exchange: An efficient tool in the modular construction of biaryl ligands

• Laurence Bonnafoux,
• Frédéric R. Leroux and
• Françoise Colobert

Beilstein J. Org. Chem. 2011, 7, 1278–1287, doi:10.3762/bjoc.7.148

• -Dimethylamino-2',6-dibromobiphenyl (1c) was obtained in an overall yield of 79% in 3 steps (Scheme 1). To introduce the methoxy group, 2,2',6-tribromobiphenyl (1a) was successively subjected to lithiation, borylation with fluorodimethoxyborane·diethyl ether, followed by oxidation with hydrogen peroxide and O

One-pot four-component synthesis of pyrimidyl and pyrazolyl substituted azulenes by glyoxylation–decarbonylative alkynylation–cyclocondensation sequences

• Charlotte F. Gers,
• Julia Rosellen,
• Eugen Merkul and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2011, 7, 1173–1181, doi:10.3762/bjoc.7.136

• , azulenes must be functionalized, either by halogenation or borylation, and some of these derivatives were found to be quite unstable [45][46]. To the best of our knowledge, no diversity-oriented multicomponent syntheses of azulenyl heterocycles have been reported so far. Here, we report the development of

Convenient methods for preparing π-conjugated linkers as building blocks for modular chemistry

• Jiří Kulhánek,
• Filip Bureš and
• Miroslav Ludwig

Beilstein J. Org. Chem. 2009, 5, No. 11, doi:10.3762/bjoc.5.11

• the Horner–Wadsworth–Emmons reaction described above. These substituted 4-bromostilbenes could be most effectively converted to target pinacol esters 5a–c via borylation (Scheme 1, Method C) utilizing bis(pinacolato)diboron (pin2B2) [39] in a mixed solvent system DMSO/dioxane ensuring good solubility

• . It should be noted here that 5a–c were also accessible via the routine sequence showed for Method B. On the contrary, borylation of 4-bromobiphenyls with pin2B2 (Method C) yielded only traces of 4a–c. Linear phenylethynylphenyl π-linkers 6a–c were gained by a Sonogashira cross-coupling between the

• . Overall 12 extended π-linkers have been easily synthesized (8 of them are new compounds) utilizing procedures such as a lithiation/reaction with triisopropyl borate/esterification with pinacol, Mizoroki–Heck coupling with vinylboronate pinacol ester, borylation with bis(pinacolato)diboron or Sonogashira