A convenient procedure for the synthesis of cyanohydrins by the addition of trimethylsilyl cyanide to aromatic aldehydes, heteroaromatic aldehydes, aliphatic aldehydes and unsaturated aldehydes catalysed by MgI2 etherate (MgI2·(OEt2)n) in good to excellent yields is described.
Asymmetric Synthesis of a New Salen Type-titanium Complex as the Catalyst for Asymmetric Trimethylsilylcyanation of Aldehydes
作者:Zheng-Chang Lin、Chinpiao Chen
DOI:10.1002/jccs.201000101
日期:2010.8
This work describes the asymmetric synthesis of a new salen‐type ligand via a Diels‐Alder reaction and Curtius rearrangement. The ligand with a norbornane skeleton was used in the trimethylsilylcyanation of aldehydes, but the enantioselectivity was 55%ee. The norborane skeleton was cleaved to destroy this rigidity, and the eanatioselectivity was thereby increased to 85%ee.
stereocenters bearing both a trifluoromethylthio (SCF3) group and a cyano group has been realized, through asymmetric organophosphine-catalyzed Mannich-typereactions. The products were obtained in high yields and moderate to high enantioselectivities. Two diastereoisomers could be isolated from each reaction (overall 25 examples), rendering this approach a viable opportunity for molecular diversity generation
<b>
Synthesis of Acrylonitriles
<i>via</i>
Mild Base Promoted Tandem Nucleophilic
<scp>Substitution‐Isomerization</scp>
of
<scp>α‐Cyanohydrin</scp>
Methanesulfonates
</b>
作者:Shiwen Liu、Lingling Meng、Xiaojun Zeng、Gerald B. Hammond、Bo Xu
DOI:10.1002/cjoc.202000579
日期:2021.4
Main observation and conclusion We have developed an efficient synthesis of acrylonitriles via mild base promoted tandem nucleophilic substitution‐isomerization of α‐cyanohydrin methanesulfonates with alkenylboronic acids. This transition metal‐free protocol works under simple and mild conditions and offers good chemical yields for a wide range of substrates and demonstrates good functional group tolerance