5 research outputs found
Synthesis of Functionalized Alkenes by a Transition-Metal-Free Zweifel Coupling
The Zweifel reaction
is a powerful method for the synthesis of
alkenes, serving as a transition-metal-free alternative to the Suzuki–Miyaura
reaction. To date, the scope of the Zweifel coupling has been rather
narrow and has focused mainly on the coupling of vinyllithium reagents
to synthesize simple aryl- and alkyl-substituted olefins. Herein,
the development of a general transition-metal-free coupling process
enabling the coupling of Grignard reagents or organolithiums is described.
This method enables the enantiospecific synthesis of a wide variety
of functionalized acyclic and cyclic olefin products
Iridium-Catalysed C-H Borylation of 2-Pyridones; Bisfunctionalisation of CC4
The high regioselectivity associated with the iridium-catalysed borylation of pyridones has been exploited to provide a very direct and efficient entry to C(10) doubly substituted CC4 variants of cytisine. Two approaches have been evaluated based on (i) C-H activation of cytisine (or an N-substituted derivative) followed by N-alkylation (to enable dimer formation) and (ii) direct C-H activation and borylation of CC4 itself. Both approaches provide access to C(10)-functionalized CC4 derivatives, but direct borylation of CC4 allows for a wider range of functional group interconversions to be tolerated.</p