Synthesis and applications of derivatives of 1,7-diazaspiro[5.5]undecane

Spiroaminals are an understudied class of heterocycle. Recently, the Barrett group reported a relatively mild approach to the most simple form of spiroaminal; 1,7-diazaspiro[5.5]undecane (I). This thesis consists of the development of novel synthetic methodologies towards the spiroaminal moiety. The first part of this thesis focuses on the synthesis of aliphatic derivatives of I through a variety of methods from the classic Barrett approach which utilises lactam II, through to de novo bidirectional approaches which utilise diphosphate V and a key Horner-Wadsworth-Emmons reaction with aldehyde VI. The second part of this thesis concentrates on the synthesis of tetrahydrospirobiquinolines and their derivatives. The methodology developed utilises simple conditions, withstands a range of functional groups, and allows many substrates to be accessed under mild conditions. These compounds showed higher aminal stability relative to their aliphatic counterparts and were further derivatised by bromination, alkylation and cross-coupling techniques, all proceeding with the retention of the aminal centre. The final part of this thesis details theattempts to complex these newly isolated compounds to a variety of elementsacross the periodictable, as well asinitial investigations into their biological activities.Open Acces