o-Nitrobenzyl as a photocleavable nitrogen protecting group for indoles, benzimidazole, and 6-chlorouracil
作者:Troy Voelker、Tim Ewell、Jean Joo、Eric D. Edstrom
DOI:10.1016/s0040-4039(97)10600-1
日期:1998.1
The potential for the o-nitrobenzyl group as an alternative nitrogen protecting group for various indoles, benzimidazole, and 6-chlorouracil was determined. Treatment of the appropriate N-H containing substrate with LiH or NaH in DMF followed by o-nitrobenzyl bromide afforded reasonable yields of N-alkylated products. To effect removal of this group, simple photolysis with 300 nm light afforded good yields of starting substrate. (C) 1997 Elsevier Science Ltd. All rights reserved.
A new palladium-mediated approach to 4-N-arylamino-1-butanols from peroxidic tetrahydrofuran and primary aromatic amines
作者:Henry F. Russell、John B. Bremner、Jennifer Bushelle-Edghill、Melissa R. Lewis、Stacey R. Thomas、Floyd Bates
DOI:10.1016/j.tetlet.2006.12.136
日期:2007.2
Reaction of primary aromatic amines with peroxidic tetrahydrofuran (THF) in the presence of hydrogen and 10%, palladium on carbon catalyst results in THF ring opening to give 4-N-arylamino-1-butanols in a good yield. The reaction mechanism is believed to involve a free-radical sequence resulting in an imino alcohol subsequently reduced to product. (c) 2007 Elsevier Ltd. All rights reserved.
Reevaluation of the 2-nitrobenzyl protecting group for nitrogen containing compounds: an application of flow photochemistry
作者:Chloe I. Wendell、Michael J. Boyd
DOI:10.1016/j.tetlet.2015.01.007
日期:2015.2
Photochemistry under continuous flow conditions has many potential benefits for photochemical reactions that are problematic in batch. The 2-nitrobenzyl moiety is a photolabile protecting group for nitrogen. However, N-deprotection is generally impractical and, therefore, has not been extensively adopted. This Letter reports significant improvements in the N-deprotection of the 2-nitrobenzyl group
An efficient strategy for N-alkylation of benzimidazoles/imidazoles in SDS-aqueous basic medium and N-alkylation induced ring opening of benzimidazoles
作者:Ankita Chakraborty、Sudipto Debnath、Tanmoy Ghosh、Dilip K. Maiti、Swapan Majumdar
DOI:10.1016/j.tet.2018.08.029
日期:2018.10
alkyl halides reaction proceeds at ambient temperature whereas in the cases of less reactive alkyl halides require 55–60 °C to complete alkylation process. N-alkylation induced ring opening of the heterocyclicring in benzimidazole derivatives to multifunctional aromaticcompounds were noticed at 60 °C when more than two equivalents of alkyl halide was used.