The Studies Of Pd-catalyzed Ortho-C-H Activation Of Aryl Amides

The transition metal palladium-catalyzed ortho-directed C–H activation hasbecome one of the most important methods for the construction of the naturalcompounds and a variety of drug molecules. Due to the coordination effect of thedirecting groups, this type of reaction can directingly fulfil the functionalisation of C–H bond to form C–C, C–N, C–O and C–X bonds (X=Cl, Br, I) avoidingprefunctionalizing of the corresponding starting materials. In this thesis, several C–Hbond functionalization methodologies for the synthesis of isoquinlinones, hydroxylisoindolones, imino/keto carboxylic acids have been demonstrated. The contents areas follows:1. We have developed a Pd-catalysed C–H activation methodology for thesynthesis of a series of N-alkyl and N-arylisoquinolones and derivatives. Reactionswere using a substoichiometric amount of Cu salts as the key oxidant and air as theterminal oxidant for the regeneration of active Pd(II) species. A comparison oforganic and inorganic salts as the additives was undertaken and the roles of thesereagents were postulated.2. The first Pd-catalyzed C–H activation/annulation reaction for the facilepreparation of hydroxyl isoindolones with near “click chemistry” efficiency ispresented. This methodology features environmentally benign reagents, short reactiontimes (within15min), high atom efficiency (loss of2H atoms), wide scope (22examples) and good yields (up to93%). A gram-scale synthesis withnonchromatographic purification is also demonstrated.3. A novel Pd-catalysed C–H activation reaction for the synthesis of biarylimino/keto carboxylic acids is developed. This reaction underwent aryl amide directedC–H activation ortho-acylation followed by ring closing and ring opening processesto give a range of biaryl imino/keto carboxylic acids. Our methodology features theutilization of a cheap and green oxidant (TBHP) as well as readily availablealdehydes.