Synthesis of Polyfunctionalized Triaryllanthanum Reagents by Using Ph<sub>3</sub>
La and Related Species as Exchange Reagents
作者:Andreas D. Benischke、Lucile Anthore-Dalion、Fabien Kohl、Paul Knochel
DOI:10.1002/chem.201801527
日期:2018.8.1
Ph3La⋅5 LiCl and the related (m‐xylyl)3La⋅5 LiCl were used as Hal/La exchange reagents (Hal=Br, I) for the preparation of various triaryl‐ and triheteroaryl‐lanthanum derivatives. These new exchange reagents are compatible with isoquinolines and some functional groups such as a nitrile or an ester. The reactivity of the resulting lanthanum compounds towards electrophiles, such as ketones, aldehydes
Naphthalene catalysed reductive lithiation of various chloroazines (1, 7, 10, 13) in the presence of different electrophiles yields, after hydrolysis, the expected functionalised heterocycles with one (2, 8), two (11, 14a–d) and three nitrogen atoms in the ring (14e,f). This methodology allowed us to trap in situ the lithium imine derived from the reaction of 2-pyridyllithium with benzonitrile, by
3-,4-Pyridyl and 4-quinolyl Grignardreagents were generated by the reaction of the corresponding phenyl sulfoxides with PhMgBr and give the adducts upon treatment with various aldehydes and ketones. The stereochemistry for the reaction was investigated.