Photochemical Alkene Isomerization for the Synthesis of Polysubstituted Furans and Pyrroles under Neutral Conditions.

A photochemical approach to polysubstituted heterocycles using UV-induced alkene isomerization is described. The method allows for the synthesis of disubstituted furans and pyrroles under mild and neutral conditions and also provides access to a class of trisubstituted furans pertinent to natural-product synthesis. The method has broad functional-group tolerance and many richly decorated heterocycles have been prepared incorporating functional groups that are unstable under Brønsted and Lewis acidic conditions.

CROSS: an efficient workflow for reaction-driven rescaffolding and side-chain optimization using robust chemical reactions and available reagents.

A novel procedure (CROSS: Computational Rescaffolding and Optimization using Synthetic Schemes) for in silico rescaffolding and side-chain optimization is reported with explicit consideration of the route of synthesis and availability of compatible chemical reagents. We have defined a set of retrosynthetic disconnections representing robust reactions, amenable for combinatorial chemistry. This rule set is used to generate virtual fragment databases from available reagents.