Nitrogen-containing π-excessive aromatic heterocycles, in particular, carbazole, indolocarbazole, benzocarbazole, and carboline are considered to be the fundamental backbone of organic chemistry for many decades due to their omnipresence in natural...

Indoles are one of the most prominent aromatic heterocycles in the organic chemistry space. Due to their widespread presence in various natural products, alkaloids, drugs, approved medicines, etc. synthesis and...

A stereoselective, redox-neutral, Brønsted acid-catalyzed cascade Prins-type cyclization between indole and aldehyde is described to access several structurally diverse indole terpenoid scaffolds in a single step. Applying this concept, stereodivergent total syntheses of nine hapalindole-type alkaloids are accomplished. Key transformations include allylation using geometrically isomeric allylboronic acid followed by a p-toluenesulfonic acid mediated deprotection–cyclization cascade.

Benzannulation of 2‐alkenylindoles with readily available aldehydes, under one‐pot sequential triple‐relay‐catalysis, provides an easy access to several structurally unique carbazoles including 2‐ and 3‐alkenylcarbazoles. This protecting group‐free method enabled one‐pot synthesis of alkaloids such as hyellazole and 6‐chlorohyellazole, and the formal syntheses of seven other alkaloids. Construction of the core structure, present in murastifoline A, murrafoline E, and related alkaloids was also demonstrated. Even conjugated 3,3′‐biscarbazoles can also be synthesized by one‐pot, two‐fold sequential triple‐relay catalysis.magnified image

An iron‐TEMPO‐catalyzed (TEMPO = 2,2,6,6‐tetramethyl‐1‐piperidinyloxy), aerobic process was developed to synthesize α‐keto amides. This reaction proceeds through a domino alcohol oxidation/oxidative cross‐dehydrogenative coupling sequence, uses 2‐hydroxyacetophenones and amines as the starting materials, and takes place under molecular oxygen, which makes the transformation highly efficient, practical, and environmentally friendly.