Synthesis of 6,7-dihydro-5H-cyclopenta[b]pyridin-5-one analogues through manganese-catalyzed oxidation of the CH2 adjacent to pyridine moiety in waterElectronic supplementary information (ESI) available. CCDC 1040117. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4gc02471k

Direct oxidation of 2,3-cyclopentenopyridine analogues to 6,7-dihydro-5 H -cyclopenta[ b ]pyridin-5-one analogues was achieved using Mn(OTf) 2 as a catalyst and t -BuOOH (65% in H 2 O) as an oxidant at 25 °C in H 2 O with high yield and excellent chemoselectivity for the first time. The catalytic system was also used efficiently for the direct oxidation of substituted benzylpyridines and 2-ethylpyridine in t -BuOH. A facile and efficient methodology is presented for the direct oxidation of 2,3-cyclopentenopyridine analogues forming 6,7-dihydro-5 H -cyclopenta[ b ]pyridin-5-one in water.