Synthesis of Polyfunctionalized Triaryllanthanum Reagents by Using Ph3La and Related Species as Exchange Reagents

• Published in: Chemistry : a European journal 2018-08, Vol.24 (43), p.11103-11109
• Main Authors: Benischke, Andreas D., Anthore‐Dalion, Lucile, Kohl, Fabien, Knochel, Paul
• Format: Article
• Language: English
• Subjects: acylation; Aldehydes; Aromatic compounds; Bromides; Exchanging; Functional groups; Halides; halogen–lanthanum exchange; Ketones; Lanthanum; Lanthanum compounds; Lithium chloride; nucleophilic substitution; Reagents; triaryllanthanum reagents
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201801527

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, N,N‐dimethylamides, and primary alkyl halides was investigated. Additionally, a Pd‐catalyzed cross‐coupling procedure with aryl bromides was developed. In exchange: 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, N,N‐dimethylamides, and primary alkyl halides was investigated (see scheme).