Rhodium(II)-catalyzedintramolecular [4 + 3] cycloadditions of dienyltriazoles have been developed, which enable the efficient synthesis of various fused 2,5-dihydroazepines. Mechanistically, the titled reaction proceeds via an interesting tandem cyclopropanation/aza-cope rearrangement.
Diversity-Oriented Approach to Novel Spirocyclics via Enyne Metathesis, Diels-Alder Reaction, and a [2+2+2] Cycloaddition as Key Steps
作者:Sambasivarao Kotha、Rashid Ali、Arti Tiwari
DOI:10.1055/s-0033-1339489
日期:——
A simple protocol for the synthesis of indane-based spirocyclics has been developed via enynemetathesis, Diels–Alderreaction, and a [2+2+2] cycloaddition as keysteps starting from indane-1,3-dione. The key diene building block was assembled by enynemetathesis. In this sequence, rongalite is used as a green reagent to prepare the sultine intermediate, which is a useful precursor to generate the
A rare example of cyclization with 5-alkynones, which possess non-polar alkynyl and less electrophilic polar keto carbonyl groups, was demonstrated. The key to promoting carbene/alkyne metathesis followed by alkylidenation with pendant CO double bonds was the Schrock-type nucleophilic reactivity of the generated chromium carbene equivalents from readily available diiodomethanes and CrCl2 by simple