demonstrated that triazolium alkynes were more reactive than their triazole counterparts in CuAAC reactions, especially with aromatic azides. The N-alkylation site integrity was maintained in all the triazolium salts prepared. alkylation - catalysis - cycloaddition - heterocycles - 1,2,3-triazolium salts
Hydroamination of Unactivated Alkenes with Aliphatic Azides
作者:Si-Ming Jia、Yi-Hang Huang、Zhan-Lin Wang、Fang-Xu Fan、Bo-Han Fan、Hao-Xiang Sun、Hao Wang、Fei Wang
DOI:10.1021/jacs.2c07643
日期:2022.9.14
efficient and highly diastereoselective intermolecular anti-Markovnikov hydroamination of unactivated alkenes with aliphatic azides in the presence of silane. The system tolerates a wide range of azides and alkenes and operates with alkene as limiting reagent. Mechanistic studies suggest a radical chain pathway that involves aminium radical formation, radical addition to alkenes and HAT from silane
我们在此报告了在硅烷存在下用脂肪族叠氮化物对未活化烯烃进行有效且高度非对映选择性的分子间抗马尔科夫尼科夫加氢胺化。该系统可耐受多种叠氮化物和烯烃,并使用烯烃作为限制试剂。机理研究表明,自由基链途径包括胺自由基的形成、烯烃的自由基加成和从硅烷到 β-胺烷基自由基的 HAT。建议使用空间大的硅烷有助于 HAT 具有出色的非对映选择性。计算分析揭示了脂肪族叠氮化物与甲硅烷基自由基活化形成胺基自由基的反应途径。
“Click” Synthesis of Nonsymmetrical Bis(1,2,3-triazoles)
作者:Jesus M. Aizpurua、Itxaso Azcune、Raluca M. Fratila、Eva Balentova、Maialen Sagartzazu-Aizpurua、Jose I. Miranda
DOI:10.1021/ol1003127
日期:2010.4.2
Unsymmetrically 1,1'-disubstituted 4,4'-bis-1H-1,2,3-triazoles 4 have been prepared from 4-ethynyl-1,2,3-triazoles 5 and azides. Following a "double-click" strategy, two complementary approaches were implemented for the preparation of the key 4-ethynyltriazole intermediates 5: (a) the stepwise Swern oxidation/Ohira-Bestman alkynylation of readily available 4-hydroxymethyl-1,2,3-triazoles 8 and (b) the stepwise cycloaddition of TMS-1,4-butadlyne 9. The method is highlighted by its compatibility with orthogonally protected and functionalized saccharide-peptide hybrids and its ability to be extended to the trisubstituted counterparts 12.