Abstract
This thesis describes development of new synthetic methods with π components and organometallic reagents using more abundant first-row transition metal catalyst such as, Nickel and Iron. In first chaper, nickel-catalyzed borylative cyclization of 1,6- and 1,7-enynes with bis(pinacolato)diboron is described. The reaction is highly chemo- and stereoselective which majorly depends on the type of enyne employed. The utility of alkenylboronates in coupling reactions and functional group transformation reactions were demonstrated. The 2nd chaper reveals nickel-catalyzed highly regioselective 1,4-addition reaction of organo boronic acids to dienones to form all-carbon quater-nary center. The catalytic reaction is compatible with a variety of aryl- and styrylboronic acids and dienones and does not require any additive for the activation of the boronic acids. Chapter 3 depicts iron promoted halocyclizations of 1,6-enynes. we have developed a simple, efficient and economical method for the synthesis of benzofuranone. This method offers several advantages including mild halogenation condition, high conversion, short reaction time and good yields. The final chapter deals about an economically efficient synthesis of vinyl carboxylic acids by iron-catalyzed hydrocarboxylation of internal alkynes using carbon dioxide as a carbon source. The α,β-unsaturated carboxylic acids could be easily transformed to corresponding benzofuran-2-one skeletons which are present in various natural product and bioactive molecules.