Repozytorium

Reaction of 2-trifluoroacetyl-1,8-bis(dimethylamino)naphthalene with strong organic bases: deprotonation of 1-NMe2 group resulting in the formation of benzo[g]indole derivatives versus nucleophilic addition to C=O group.

Autorzy

Alexander S. Antonov

Svetlana G. Kachalkina

Alexander F. Pozharskii

Gennady S. Borodkin

Aleksander Filarowski

Rok wydania

2017

Czasopismo

Tetrahedron

Numer woluminu

73

Strony

3452-3457

DOI

10.1016/j.tet.2017.05.013

Kolekcja

Naukowa

Język

Angielski

Typ publikacji

Artykuł

Streszczenie

A novel approach to pyrrole ring closure in 2-trifluoroacetyl- and 2-ethoxycarbonyl-1,8-bis(dimethylamino)naphthalenes via treatment with 2-lithium-1,8-bis(dimethylamino)naphthalene producing the corresponding benzo[g]indole derivatives, was examined with different alkyl- and aryllithium compounds as well as with LDA. It was found that the highest yields of benzo[g]indoles (up to 70%) are obtained with aryllithium reagents when they contain NMe2 group in ortho-position to the carbanionic centre. In all other cases the formation of acyclic alcohol arising from ordinary intermolecular addition of the carbanion to the CO group strongly prevails. The dramatic facilitation of deprotonation of the N-Me group in substrate followed by pyrrolic cyclization in the case of 2-lithium-N,N-dimethylanilines was explained through a specific structure of the reaction transition state.

Słowa kluczowe

indole, proton sponge, organolithiums, alcohol, fluorine

Adres publiczny

https://doi.org/10.1016/j.tet.2017.05.013

Strona internetowa wydawcy

http://www.elsevier.com

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