Cooperative Catalysis-Enabled (4 + 3) Cycloaddition of 2-Indolylmethanols with Generated -Naphthoquinone Methides.

A cooperative catalysis-enabled (4 + 3) cycloaddition of 2-indolylmethanols with -naphthoquinone methides (-NQMs), which were generated from enynones, has been established in the presence of silver/Brønsted acid cocatalysts. In the reaction pathway, the key -NQM intermediates were formed through Ag(I)-catalyzed cyclization of enynones, while the indole-based carbocation intermediates were generated via Brønsted acid-catalyzed dehydration of 2-indolylmethanols. By this approach, a wide range of seven-membered cyclohepta[]indoles were synthesized in good yields with high efficiency under mild reaction conditions, which serves as a useful strategy toward constructing indole-fused seven-membered rings.

Protein composition analysis of polyhedra matrix of Bombyx mori nucleopolyhedrovirus (BmNPV) showed powerful capacity of polyhedra to encapsulate foreign proteins.

Polyhedra can encapsulate other proteins and have potential applications as protein stabilizers. The extremely stable polyhedra matrix may provide a platform for future engineered micro-crystal devices. However, the protein composition of the polyhedra matrix remains largely unknown.