Synthesis of arylaminotetrazoles by ZnCl2/AlCl3/silica as an efficient heterogeneous catalyst
摘要:
Arylaminotetrazoles were efficiently synthesized from secondary arylcyanamides by application of ZnCl2/AlCl3/silica as a reusable heterogeneous Lewis acid catalyst. 5-Arylamino-1-tetrazoles can be obtained from arylcyanamides carrying electron-withdrawing substituents on the aryl ring, while with electron-releasing groups 1-aryl-5-amino-1-tetrazoles will be produced. The former isomer is also produced within longer reaction times (similar to 20 h) even with electron-releasing groups.
Selective Gold-Catalysed Synthesis of Cyanamides and 1-Substituted 1<i>H</i>
-Tetrazol-5-Amines from Isocyanides
作者:Karel Škoch、Ivana Císařová、Petr Štěpnička
DOI:10.1002/chem.201803252
日期:2018.9.18
The newly discovered gold‐catalysed reaction of isocyanides with hydrazoic acid generated in situ from trimethylsilyl azide and methanol (or, alternatively, from NaN3/AcOH) produces either cyanamides or 1‐substituted 1H‐tetrazol‐5‐amines, depending on the amount of available HN3. The reaction proceeds selectively and in generally high yields of either product, thus providing a particularly convenient
A one-pot preparation of cyanamide from dithiocarbamate using molecular iodine
作者:Jayashree Nath、Bhisma K. Patel、Latonglila Jamir、Upasana Bora Sinha、K. V. V. V. Satyanarayana
DOI:10.1039/b914283p
日期:——
method for the synthesis of cyanamides from dithiocarbamate salts via a double desulfurization strategy using molecular iodine is disclosed. Dithiocarbamates, by the action of iodine yield isothiocyanates in situ, which on treatment with aqueous NH3 give thioureas. The thioureas so generated undergo further oxidative desulfurization with I2 giving corresponding cyanamides in good yields. Environmental
aldehydes to cyanamides was developed featuring a wide substrate scope and great functional group tolerability. This method allows for transformations of readily available, inexpensive, and abundant aldehydes to highly valuable cyanamides in a pot, atom, and step-economical manner with a green nitrogen source. This protocol will serve as a robust tool for the installation of the cyanamide moiety in various
A cascade process for directly converting nitriles (RCN) to cyanamides (RNHCN) <i>via</i> SO<sub>2</sub>F<sub>2</sub>-activated Tiemann rearrangement
作者:Guofu Zhang、Yiyong Zhao、Chengrong Ding
DOI:10.1039/c9ob01547g
日期:——
practical process for the direct conversion of nitriles to cyanamides was newly discovered and exhibited a wide substrate scope as well as great functional group-tolerability (36 examples). In this efficient strategy, the in situ generated amidoximes obtained from the reaction of nitriles with hydroxylamine subsequently underwent Tiemann rearrangement, producing the corresponding cyanamides with great
N-Arylphthalimides can be converted to isoindoles by a two electron reduction and silylation. Cycloaddition with acetylenic dienophiles leads to naphthoquinonemonoimines, which show absorption maxima in the NIR region up to 800 nm.