Divergent synthesis of cyclopropane-containing fragments and lead-like compounds for drug discovery
File(s)
Author(s)
Chawner, Stephen John
Type
Thesis or dissertation
Abstract
The cyclopropane ring is key to a large number of medicinally‑relevant compounds that possess a broad spectrum of biological activities. This thesis details the preparation of novel bifunctional cyclopropanes through a divergent functionalisation approach utilising two readily accessible cyclopropyl‑scaffolds. The cyclopropanes generated sampled new areas of chemical space whilst being suitable 3‑dimensional fragments and lead-like compounds for drug discovery. A novel CoII-catalysed cyclopropanation generates two diastereoisomeric bifunctional cyclopropyl-scaffolds from commercially available reagents in an excellent yield and can be conducted on multi-gram scales. Asymmetric cyclopropanation has been
explored with max ee = 73%. Divergent functionalisation of the ester was explored, utilising hydrolysis, reduction and amidation reactions to create a variety of functionalised cyclopropyl sulfides. The sulfide synthetic handle was oxidised to give
the corresponding sulfoxides or sulfone selectively. Sulfoxide–magnesium exchange was explored and the cyclopropyl-organometallic species generated was trapped with a variety of electrophiles to create a diverse range of cyclopropane-containing
products. The cyclopropyl-organometallic species was also utilised in Negishi cross-coupling, proving to be a versatile method to attach an aromatic or heteroaromatic directly onto the cyclopropane ring.
explored with max ee = 73%. Divergent functionalisation of the ester was explored, utilising hydrolysis, reduction and amidation reactions to create a variety of functionalised cyclopropyl sulfides. The sulfide synthetic handle was oxidised to give
the corresponding sulfoxides or sulfone selectively. Sulfoxide–magnesium exchange was explored and the cyclopropyl-organometallic species generated was trapped with a variety of electrophiles to create a diverse range of cyclopropane-containing
products. The cyclopropyl-organometallic species was also utilised in Negishi cross-coupling, proving to be a versatile method to attach an aromatic or heteroaromatic directly onto the cyclopropane ring.
Version
Open Access
Date Issued
2017-09
Date Awarded
2018-01
Advisor
Bull, James
Publisher Department
Chemistry
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)