Metal-/solvent-free oxidative [4 + 2]/[3 + 2] annulation of 2-ethynylbenzaldehydes with arylalkenes: facile synthesis of benzo[a]fluoren-5-ones

DTBP-mediated oxidative [4 + 2]/[3 + 2] annulation between 2-alkynylbenzaldehydes and arylalkenes toward benzo[ a ]fluoren-5-ones under metal-/solvent-free conditions is presented.