Rapid regio- and multi-coupling reactivity of 2,3-dibromobenzofurans with atom-economic triarylbismuths under palladium catalysis

• Maddali L. N. Rao,
• Jalindar B. Talode and
• Venneti N. Murty

Beilstein J. Org. Chem. 2016, 12, 2065–2076, doi:10.3762/bjoc.12.195

• : bromobenzofuran coupling; cross-coupling; palladium; regio-selective; triarylbismuth; Introduction The benzofuran scaffold is present in various biologically active molecules [1][2][3][4][5][6][7][8], natural products [9][10][11][12][13][14][15] and also part of various functional materials [16]. Importantly

• bromobenzofurans with triarylbismuth reagents under palladium coupling conditions. Results and Discussion This study was initiated with 2,3-dibromobenzofuran for the investigation of the regio-selective coupling using a triarylbismuth reagent in substoichiometric amounts under Pd-catalyzed conditions (Table 1). A

• -dibromobenzofuran (1.1) and 1 equiv of bismuth reagent gave 86% yield (Table 1, entry 10). A few control reactions without base or palladium catalyst showed inferior or no cross-coupling reactivity (Table 1, entries 11 and 12). This investigation results that the desired regio-selective cross-coupling reactivity

Synthesis of the C8’-epimeric thymine pyranosyl amino acid core of amipurimycin

• Pramod R. Markad,
• Navanath Kumbhar and
• Dilip D. Dhavale

Beilstein J. Org. Chem. 2016, 12, 1765–1771, doi:10.3762/bjoc.12.165

• -glucose derived alcohol 3 in 13 steps and 14% overall yield. Thus, the Sharpless asymmetric epoxidation of allyl alcohol 7 followed by trimethyl borate mediated regio-selective oxirane ring opening with azide, afforded azido diol 10. The acid-catalyzed 1,2-acetonide ring opening in 10 concomitantly led to