Executive Summary : | The discovery of catalysts is a breakthrough in organic synthesis. In recent days, chemists have started looking for metal-free organic reactions which are practical, greener, and easy to scale up for the industrial processes. Phase transfer catalysts (PTC) are one of the preferred choices to carry out the organic transformation in a sustainable manner as it uses a biphasic medium and reduces the utilisation of organic solvents. In particular, chiral PTC plays a significant role in asymmetric synthesis in synthesising enantiomerically enriched molecules on a larger scale. This research proposal mainly focuses on designing and synthesising axial-chiral phase transfer catalysts such as biisoquinoline based phase transfer catalysts and binaphthyl-based phase transfer catalysts and their applications in developing new enantioselective reactions. The biisoquinoline and binaphthyl derived chiral PTCs with two quaternary centres will be synthesised and utilised for the first time in asymmetric synthesis. In case the hydrophobicity of the new catalysts is not sufficient, then appropriate bigger alkyl groups will be introduced in these PTCs, because, in a PTC reaction, the reactivity and selectivity are highly dependent on the lipophilicity and the large ionic radius of the chiral cation. Initially, the new chiral PTC will be utilised for asymmetric alkylation of 1-methyldihydronaphthalen-2-one with an alkyl halide in the presence of aq. NaOH in an appropriate organic solvent. Then, the PTC will be utilised to develop new enantioselective reactions such as a) Asymmetric Friedel-Crafts hydroxyarylation of indole, b) Asymmetric synthesis of benzopyrans, c) Asymmetric synthesis of diazaphosphinanes coumarin derivatives, d) Asymmetric synthesis of aminophosphonates, and e) Asymmetric synthesis of 1,5-benzodiazepine derivatives. To show the usefulness of the newly synthesised axial-chiral PTC and the freshly developed chiral PTC catalysed asymmetric reactions, several biologically important enantiopure natural products such as (-)-Wy-16,225 (bridged aminotetralin; analgesic agent), LAF-389 (anti-cancer), (-)-antofine (angiogenesis suppresser) and (+)-podocarp-8-en-13-one (important intermediate for the synthesis of several diterpenes) will be synthesised using newly developed asymmetric reactions or chiral PTC in the key step. |