Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

• Marco Manenti,
• Leonardo Lo Presti,
• Giorgio Molteni and
• Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

• . Results and Discussion We began our investigation using the known (R)-1-methylisatin-derived N-tert-butanesulfinyl ketimine 1a, bis(pinacolato)diboron, CuSO4/(Cy)3P catalyst and benzylamine, as reported in Scheme 1. The first reaction was carried out at room temperature in toluene/water (5:1), as

• diffraction analysis and proved to be single diastereoisomers and atropisomers. A plausible mechanism for the one-pot Cu(II)-catalyzed Bpin addition to the isatin-derived ketimine substrate and subsequent homocoupling is described. Keywords: atropoisomer; bis(pinacolato)diboron; 3,3′-bisoxindole; N-tert

• -butanesulfinyl ketimine; homocoupling; Introduction As bioisosteres of carboxylic acid derivatives, boronic acids have recently emerged as a novel chemotype in drug design, with a number of boron-containing compounds recently being approved by the FDA [1][2][3][4]. In particular, α- and β-aminoboronic acids are