A novel spirocyclic scaffold accessed via tandem Claisen rearrangement/intramolecular oxa-Michael addition

• Anastasia Vepreva,
• Alexander Yanovich,
• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1649–1655, doi:10.3762/bjoc.18.177

• insertion of carbenes derived from diazo arylidene succinimides (DAS) into the O–H bond of phenols is described. The initial adducts underwent a thermally promoted Claisen rearrangement followed by DABCO-catalyzed intramolecular 5-exo-trig oxa-Michael addition. Keywords: Claisen rearrangement; diazo

• arylidene succinimides; intramolecular oxa-Michael addition; rhodium(II) carbene O–H insertion; spirocycles; Introduction Spirocycles undoubtedly occupy a special place in drug design [1] and, in general, spirocyclic compounds intended for the interrogation of biological targets have been associated with

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

• 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