02230nas a2200193   4500008004100000245009300041210006900134260000800203300001600211490000700227520158500234100001401819700001901833700001701852700001801869700001401887700001501901856012001916       2017                        eng d00aSelective C-H bond oxidation catalyzed by the Fe-bTAML complex: mechanistic implications0 aSelective CH bond oxidation catalyzed by the FebTAML complex mec  cSEP  a10852-108600 v563 aNonheme iron complexes bearing tetradentate N-atom-donor ligands with cis labile sites show great promise for chemoselective aliphatic C-H hydroxylation. However, several challenges still limit their widespread application. We report a mechanism-guided development of a peroxidase mimicking iron complex based on the bTAML macrocyclic ligand framework (Fe-bTAML: biuret-modified tetraamido macrocyclic ligand) as a catalyst to perform selective oxidation of unactivated 3° bonds with unprecedented regioselectivity (3°:2° of 110:1 for adamantane oxidation), high stereoretention (99%), and turnover numbers (TONs) up to 300 using mCPBA as the oxidant. Ligand decomposition pathways involving acid-induced demetalation were identified, and this led to the development of more robust and efficient Fe-bTAML complexes that catalyzed chemoselective C-H oxidation. Mechanistic studies, which include correlation of the product formed with the FeV(O) reactive intermediates generated during the reaction, indicate that the major pathway involves the cleavage of C-H bonds by FeV(O). When these oxidations were performed in the presence of air, the yield of the oxidized product doubled, but the stereoretention remained unchanged. On the basis of 18O labeling and other mechanistic studies, we propose a mechanism that involves the dual activation of mCPBA and O2 by Fe-bTAML, leading to formation of the FeV(O) intermediate. This high-valent iron oxo remains the active intermediate for most of the reaction, resulting in high regio- and stereoselectivity during product formation. 1 aGhosh, M.1 aPattanayak, S.1 aDhar, B., B.1 aSingh, K., K.1 aPanda, C.1 aGupta, Sen  uhttps://library.ncl.res.in/content/selective-c-h-bond-oxidation-catalyzed-fe-btaml-complex-mechanistic-implications