ABSTRACT
A diastereoselective synthesis of highly substituted aminobicyclo[4.3.0]nonanes has been attained using a one-pot multi-bond forming process. A four-step synthetic route was developed for the efficient synthesis of a series of C-7 substituted hept-2-en-6-yn-1-ols. These compounds were then investigated as substrates for a one-pot, three-step tandem process involving a palladium(ii)-catalysed Overman rearrangement, a ruthenium(ii)-catalysed ring closing enyne metathesis reaction followed by a hydrogen bond directed Diels-Alder reaction. The optimisation of the one-pot process has allowed the rapid preparation of a library of aminobicyclo[4.3.0]nonanes with significant molecular complexity and up to four stereogenic centres.
ABSTRACT
A highly efficient one-pot multistep process involving an asymmetric Pd(II)-catalyzed Overman rearrangement and a Ru(II)-catalyzed ring-closing metathesis reaction has been developed for the preparation of (R)- or (S)-aminocyclopenta-2-enes. The rapid strategy employed and the relatively mild conditions of the one-pot process allowed the multigram synthesis of the carbocycles in high enantiomeric excess (92% ee). The synthetic utility of these compounds was demonstrated by the stereoselective incorporation of hydroxyl groups, generating cis-4- and cis-5-aminocyclopenta-2-en-1-ols, important building blocks for medicinal chemistry.
Subject(s)
Cyclopentanes/chemical synthesis , Chemistry, Pharmaceutical , Cyclopentanes/chemistry , Molecular Structure , Palladium/chemistry , Ruthenium/chemistry , StereoisomerismABSTRACT
A rapid and general approach for the synthesis of amino-substituted indanes and tetralins from readily available alkyne-derived allylic alcohols via consecutive multibond-forming tandem processes has been developed. In the first one-pot tandem process, a series of cyclic dienes were prepared using an Overman rearrangement under thermal conditions, followed by a ruthenium(II)-catalyzed ring closing enyne metathesis reaction. The resulting exo-dienes were then subjected to a second one-pot tandem process involving a highly regioselective Diels-Alder reaction with alkynes, quinones or nitriles and a subsequent oxidation step to give a diverse library of C-1 amino-substituted indanes and tetralins in good overall yields.
Subject(s)
Indans/chemical synthesis , Tetrahydronaphthalenes/chemical synthesis , Indans/chemistry , Molecular Structure , Propanols/chemistry , Tetrahydronaphthalenes/chemistryABSTRACT
A one-pot tandem process involving an Overman rearrangement, ring closing enyne metathesis and a hydrogen bonding directed Diels-Alder reaction has been developed for the efficient diastereoselective synthesis of functionalised amino substituted tetralin and indene ring systems.