Divergent Annulations of 5,6‐Dihydro‐4H‐1,2‐Oxazine N‐Oxides and Enol Diazoacetates for the Switchable Chemoselective Synthesis of Fused 1,2‐Oxazine Derivatives

Divergent Annulations of 5,6‐Dihydro‐4H‐1,2‐Oxazine N‐Oxides and Enol Diazoacetates for the Switchable Chemoselective Synthesis of Fused 1,2‐Oxazine Derivatives Full article

Journal

European Journal of Organic Chemistry
ISSN: 1434-193X , E-ISSN: 1099-0690

Output data

Year: 2024, Volume: 27, Number: 45, Article number : e202400768, Pages count : DOI: 10.1002/ejoc.202400768

Authors

Ostarkov Stepan N. ^1,2 , Lichtenstein Yana I. ² , Antonova Yulia A. ² , Nelyubina Yulia V. ³ , Lesnikov Vladislav K. ² , Tabolin Andrey A. ²

Affiliations

1	Department of Chemistry M. V. Lomonosov Moscow State University Leninskie gory 1 Moscow 119991 Russian Federation
2	FSBIS N D Zelinsky Institute of Organic Chemistry of the Russian Academy of Sciences, Laboratory of organic and metal-organic nitrogen-oxygen systems, RUSSIAN FEDERATION
3	FSBSI A N Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Center for molecular composition studies, RUSSIAN FEDERATION

Reactions of 5,6-dihydro-4H-1,2-oxazine N-oxides with enol diazoacetates were studied. A particular reaction path depends on the amount of catalyst and the order of the addition of the substrates. Use of Rh2(Oct)4 (2 mol.%) leads to chemoselective [3+3]-annulation producing 1,2-oxazine-fused 1,2-oxazine derivatives. With lower catalyst loadings (0.03 mol.%) enol diazoacetates are converted to cyclopropene derivatives, which in situ react with 1,2-oxazine N-oxides via tandem [3+2]-cycloaddition-rearrangement producing oxazine-fused aziridines. Both transformations showed a wide substrate scope and produced target products with good yields and diastereoselectivity, thus allowing selective preparation of these rare heterocyclic systems. A mechanistic rationale for observed chemo- and stereo- selectivities was proposed.

Ostarkov S.N. , Lichtenstein Y.I. , Antonova Y.A. , Nelyubina Y.V. , Lesnikov V.K. , Tabolin A.A.
Divergent Annulations of 5,6‐Dihydro‐4H‐1,2‐Oxazine N‐Oxides and Enol Diazoacetates for the Switchable Chemoselective Synthesis of Fused 1,2‐Oxazine Derivatives
European Journal of Organic Chemistry. 2024. V.27. N45. e202400768 . DOI: 10.1002/ejoc.202400768 WOS Scopus OpenAlex

≡ Web of science:	WOS:001357552000001
≡ Scopus:	2-s2.0-85208502364
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