Rhodium and Palladium Catalyzed Organic Transformations in the Synthesis of Small Heterocyclic Compounds

This thesis describes new applications of rhodium and palladium catalyzed asymmetric ring-opening of strained alkenes, and subsequently, the use of rhodium and palladium catalysts in the development of multimetal-catalyzed domino reactions. The contents are divided into four chapters. Chapter 1 describes two projects in the field of asymmetric ring-opening (ARO). The first project reports the functionalization of enantioenriched ARO products through diastereoselective Friedel-crafts alkylation to obtain aryltetracyclic products. Both cis and trans products can be obtained with moderate to high regio-, diastereo- and enantioselectivities. The second project details ongoing work on the development of an enantioselective Rh-catalyzed cascade reaction, where cycloisomerization of an o-alkynylphenol affords a new vinyl-rhodium species that can undergo ARO with meso oxabicyclic alkenes. Chapter 2 describes the development of a one-pot synthesis of chiral dihydrobenzofurans which combines Rh-catalyzed ARO and Pd-catalyzed C-O cross-coupling in a one-pot reaction sequence. The product can be obtained in high yield and enantioselectivity without isolation of intermediates. Chapter 3 describes the first successful enantioselective multimetal-catalyzed domino reaction, which features Rh/chiral diene catalyzed hydroarylation of vinylpyridines, followed by Pd/phosphine catalyzed C-O cross-coupling to afford enantioenriched aza-dibenzoxepine products. Current work on developing an enantioselective Ru/Pd catalyzed reaction to access oxindoles with a quaternary stereocentre is also disclosed. Chapter 4 describes the first report of a three component, three catalyst (3C-3C) domino reaction that furnishes aza-dibenzazepines. Two routes are disclosed to access these highly functionalized heterocyclic compounds from different building blocks. A 1H NMR spectroscopy study highlights the time-resolution strategy involved in this Rh/Pd-catalyzed domino reaction.Ph.D