General and Efficient Insertion of Carbons Carrying Benzotriazole
摘要:
Anions formed from the lithiation of 1-(1-benzotriazolylalkyl)benzotriazoles (1, 6) and 1-(1-methylthioalkyl)benzotriazoles (10 and 10a) with n-BuLi underwent additions to cyclic and acyclic ketones giving intermediates 3a-f, 7b-f, and 11b-d, respectively, in excellent yields. Thermal rearrangements of intermediates 3a,b,d-f and 7b-d,f in the presence of zinc bromide provided one-carbon chain-extended or ring-expanded cc-benzotriazolyl ketones 4a,b,d-f and 8b-d,f in moderate yields with excellent regioselectivity. By contrast, intermediates 11b-d on treatment with zinc bromide loose a molecule of benzotriazole followed by intramolecular cyclization of the resulting intermediates 12b-d to provide the 2,3- and 1,2,3-substituted indenes 13b-d in good yields.
Acid-Mediated Denitrogenation/Rearrangement/Coupling of Benzyl Azides with Triazolyl-Substituted Cycloalkanones
作者:Ying Fu、Zhengyin Du、Yang Che、Rui Wang
DOI:10.1055/s-0037-1610747
日期:2020.3
Organic molecules containing α-triazolyl or β-amino cyclic ketone fragments have been individually proven to show good bioactivities and to be useful in asymmetric and pharmaceutical syntheses. A triflic acid-promoted simple and efficient method for the synthesis of unsymmetrical α-triazolyl-α′-(aminomethyl)cycloalkanones from benzyl azides and α-triazolylcycloalkanones has been developed. A series
We have developed an efficient, metal-free, convenient and relatively cheap method for iodine-induced direct alkylation of azoles via in situ formed alkyliodide. A series of heterocyclic derivatives are readily prepared under mild conditions in moderate to good yields and high regioselectivity. (C) 2012 Elsevier Ltd. All rights reserved.