Atom Transfer Radical Cyclisation Reactions in Organic Synthesis

Abstract

A new method for the synthesis of naphthalenes has been recently discovered.The Atom Transfer Radical Cyclisation (ATRC) of diverse 2-allylphenyl2',2',2'-trichloroacetates in the presence of a Cu complex affordschloronaphthalenes in good yields using either microwave or thermolytic methodsof activation. A mechanism for the benzannulation reaction is proposed andexperiments presented in order to validate this hypothesis. The use of1,3-bis(2,6-diisopropylphenyl)imidazolium copper(I) chloride [(IPr)CuCl)] alongwith other metal carbenes is compared to the already reported CuCl/ligandsystem.Since the scope and synthetic utility of this new benzannulation reaction isrestricted due to the use of the MW reactor, a solvent in which the thermalreaction can take place is reported, proving its efficiency in the synthesis of arange of substituted naphthalenes.The potential and versatility of the benzannulation reaction has been investigated.Studies towards the synthesis of gilvocarcin M which contains a tetracyclicaromatic core are presented. Gilvocarcins have potential use as anti-cancer agentsand represent a member of the C-aryl glycosides found in natural products.Gilvocarcin M is a challenging target because there are a sparse number of totalsyntheses reported in the literature.The ATRC reaction of (vinyl)phenyl trichloroacetate has also been investigated,affording the synthesis of functionalised coumarins. The mechanism of thisreaction has also been investigated, establishing that, in some cases, aretro-Kharasch reaction is observed.

Date of Award	31 Dec 2009
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Peter Quayle (Supervisor)