Tropane and Related Alkaloid Skeletons via a Radical [3+3]-Annulation Process

A mild and simple protocol for the synthesis of 8-azabicyclo[3.2.1]octane and 9-azabicyclo[3.3.1]nonane derivatives is described. It provides these valuable bicyclic alkaloid skeletons in good yields and high levels of diastereoselectivity from simple and readily available starting materials using visible-light photoredox catalysis. This unprecedented annulation process takes advantage of the unique reactivity of ethyl 2-(acetoxymethyl)acrylate as a 1,3-bis radical acceptor and of cyclic N,N-dialkylanilines as radical 1,3-bis radical donors. The success of this process relies on efficient electron transfer processes and highly selective deprotonation of aminium radical cations leading to the key α-amino radical intermediates.

Tropane and Related Alkaloid Skeletons via a Radical [3+3]-Annulation Process

A mild and simple protocol for the synthesis of 8-azabicyclo[3.2.1]octane and 9-azabicyclo[3.3.1]nonane derivatives is described. It provides these valuable bicyclic alkaloid skeletons in good yields and high levels of diastereoselectivity from simple and readily available starting materials using visible-light photoredox catalysis. This unprecedented annulation process takes advantage of the unique reactivity of ethyl 2-(acetoxymethyl)acrylate as a 1,3-bis radical acceptor and of cyclic N,N-dialkylanilines as radical 1,3-bis radical donors. The success of this process relies on efficient electron transfer processes and highly selective deprotonation of aminium radical cations leading to the key α-amino radical intermediates.

Aaptamine-Related Alkaloid from the Marine Sponge Aaptos aaptos

A new aaptamine-related alkaloid, 1,3-dioxolo [4,5- d] benzo [ de]-1,6-naphthyridine (methylenedioxyaaptamine, 1), was isolated from the organic extracts of the Bornean marine sponge Aaptos aaptos, together with a known aaptamine derivative, 8,9,9-trimethoxy-9 H-benzo [ de]-1,6-naphthyridine (2). The structure of compound 1 was elucidated by interpretation of its spectroscopic data. Two compounds were tested for their cytotoxic potentials against adult T-cell leukemia (ATL) cells, and compound 1 showed moderate cytotoxic potential.