Unusual highly diastereoselective Rh(II)-catalyzed dimerization of 3-diazo-2-arylidenesuccinimides provides access to a new dibenzazulene scaffold

• Anastasia Vepreva,
• Alexander S. Bunev,
• Andrey Yu. Kudinov,
• Grigory Kantin,
• Mikhail Krasavin and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2022, 18, 533–538, doi:10.3762/bjoc.18.55

• shown to strongly depend on the nature of the substituents in the diazo substrate. The new reaction provides access to dibenzoazulenodipyrrole and indenopyrrole derivatives in moderate to high yield. Dibenzoazulenodipyrroles bearing alkyl substituents at the nitrogen atom showed pronounced cytotoxocity

• against the A549 human lung adenocarcinoma cell line while N-aryl analogs were non-cytotoxic. Keywords: diazo arylidene succinimides; dibenzoazulenodipyrroles; indenopyrroles; Rh2(esp)2-catalyzed decomposition; unsymmetrical dimers; Introduction 3-Diazo-2-arylidenesuccinimides 1 (DAS) are heterocyclic

• diastereomer 2a is indicative of a sequence of concerted processes with an unambiguous stereochemistry control at each step where stereogenic centers are formed. Dibenzoazulenodipyrroles 2 have a pronounced three-dimensional character which make this chemotype promising as probe for protein–protein