4 research outputs found
Stereodivergent Synthesis of 3‑Aminooxindole Derivatives Containing Vicinal Tetrasubstituted Stereocenters via the Mannich Reaction
A highly
enantioselective stereodivergent synthesis of 3-aminooxindole
derivatives was accomplished via asymmetric Mannich reaction between
2-substituted benzofuran-3-one and isatin-derived ketimines. Both <i>anti</i> and <i>syn</i>-selective chiral 3,3-disubstituted
amino oxindoles bearing two adjacent tetrasubstituted stereogenic
centers with high yield and excellent enantioselectivities were obtained
using readily available cinchona-alkaloid derived organocatalysts.
The control experiment revealed that oxygen atom present in the benzofuran
ring played an important role in switching diastereodivergence. The
obtained Mannich product was further transformed into a biologically
important 2,3-dihydrobenzofuran derivative having three contiguous
stereocenters with no loss of enantioselectivity
Stereodivergent Synthesis of 3‑Aminooxindole Derivatives Containing Vicinal Tetrasubstituted Stereocenters via the Mannich Reaction
A highly
enantioselective stereodivergent synthesis of 3-aminooxindole
derivatives was accomplished via asymmetric Mannich reaction between
2-substituted benzofuran-3-one and isatin-derived ketimines. Both <i>anti</i> and <i>syn</i>-selective chiral 3,3-disubstituted
amino oxindoles bearing two adjacent tetrasubstituted stereogenic
centers with high yield and excellent enantioselectivities were obtained
using readily available cinchona-alkaloid derived organocatalysts.
The control experiment revealed that oxygen atom present in the benzofuran
ring played an important role in switching diastereodivergence. The
obtained Mannich product was further transformed into a biologically
important 2,3-dihydrobenzofuran derivative having three contiguous
stereocenters with no loss of enantioselectivity
Stereodivergent Synthesis of 3‑Aminooxindole Derivatives Containing Vicinal Tetrasubstituted Stereocenters via the Mannich Reaction
A highly
enantioselective stereodivergent synthesis of 3-aminooxindole
derivatives was accomplished via asymmetric Mannich reaction between
2-substituted benzofuran-3-one and isatin-derived ketimines. Both <i>anti</i> and <i>syn</i>-selective chiral 3,3-disubstituted
amino oxindoles bearing two adjacent tetrasubstituted stereogenic
centers with high yield and excellent enantioselectivities were obtained
using readily available cinchona-alkaloid derived organocatalysts.
The control experiment revealed that oxygen atom present in the benzofuran
ring played an important role in switching diastereodivergence. The
obtained Mannich product was further transformed into a biologically
important 2,3-dihydrobenzofuran derivative having three contiguous
stereocenters with no loss of enantioselectivity
Diastereo- and Enantioselective Synthesis of 2,2-Disubstituted Benzofuran-3-one Bearing Adjacent Quaternary and Tertiary Stereocenters
The
first highly diastereo- and enantioselective synthesis of armeniaspirol
analogues was achieved using L-proline derived bifunctional
squaramide which outperformed commonly used organocatalysts. Excellent
yield (up to 99%) with diastereoselectivity (up to 99:1) and enantioselectivity
(up to 99%) were obtained for a wide range of substrates