Albeit nontrivial, the long withstanding challenge of developing new chemical space for natural products of biological importance depends heavily on the development of new synthetic methods. With the increase in drug-resistance today, the expansion of chemical knowledge within the realm of natural products continues to play a vital role in biomedical research. To this end, strategies that develop five-membered carbo- or heterocyclic compounds are of interest to the synthetic community because of their prominence in natural products and pharmaceuticals.
In contrast to common [N+2]-annulation strategies, in generating three, and five-membered motifs, we demonstrate the use of carbenoid strategies, via an [N+1] strategy, provide an alternative to accessing structural motifs of biological importance. We highlight the successful implementation of our strategy, in developing fully substituted carbon centers, with a focus on two classes of heterocycles: the C3-spirofused oxindole, and the 2,3-dihydrobenzfuran.