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Sequential Acylation/Silylation/Hetero‐Claisen Rearrangement of Nitroalkanes for the Synthesis of Protected Hydroxyoxime Derivatives
Author(s) -
Antonova Yulia A.,
Ioffe Sema L.,
Sukhorukov Alexey Yu.,
Tabolin Andrey A.
Publication year - 2021
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.202100469
Subject(s) - chemistry , silylation , acylation , trifluoromethanesulfonate , moiety , nitronate , oxime , deprotonation , organic chemistry , substrate (aquarium) , claisen rearrangement , benzoyl chloride , medicinal chemistry , nitro , alkyl , catalysis , oceanography , ion , geology
Sequential acylation‐silylation of nitroalkanes leads to O ‐silylated α‐acyloxyoximes in high yields. The first step of the reaction involves deprotonation of nitro compound with sodium hydride promoted by DBU or alcohol/15‐crown‐5 system followed by treatment with acyl chloride. In situ generated acyl nitronate is further silylated by silyl triflate that triggers hetero‐Claisen [3,3]‐rearrangement within N ‐acyloxyenamine moiety furnishing orthogonally protected oxime derivatives. The procedure has large substrate scope for both nitroalkanes and acylating agents (acyl chlorides, chloroformates) and allows tuning of reaction conditions depending on the particular type of substrate. Application of obtained oxime derivatives in organic synthesis is demonstrated.