Details

Autor(en) / Beteiligte

• Devillard, Marc
• Ehlers, Andreas
• Siegler, Maxime A.
• van der Vlugt, Jarl Ivar

Titel

Selective Carbanion–Pyridine Coordination of a Reactive P,N Ligand to RhI

Ist Teil von

• Chemistry : a European journal, 2019-03, Vol.25 (15), p.3875-3883

Ort / Verlag

Weinheim: Wiley Subscription Services, Inc

Erscheinungsjahr

2019

Link zum Volltext

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Ligands with reactive carbon sites in the periphery of a metal center have emerged as a powerful approach for metal–ligand bond activation. These reactive carbon sites are commonly generated by deprotonation strategies. Carbon–silicon bond cleavage is a potential alternative to access such constructs. Herein, the monodesilylation of bis‐silyl‐substituted P,N scaffold PNSi2 in the coordination sphere of [RhI(Cl)(CO)(PNSi2)] (1) with sodium azide is disclosed. This affords a unique dinucleating anionic κ2‐C,N‐κ1‐P ligand with a carbanionic methine carbon atom directly bound to rhodium as part of a four‐membered Rh‐N‐C‐C rhodacycle. This dimer undergoes meta‐pyridine C−H activation facilitated by weak bases, which leads to a desymmetrization of the system and provides a σ,π‐bridging 3‐pyridyl fragment bound to RhI. The facile Si−C cleavage strategy may pave the way to studying the reactivity and functionalization of a variety of κ2‐C,N‐coordinated pyridine scaffolds for selective transformations. To C or not to C: The first selective P,N‐to‐C,N ligation switch in the coordination sphere of a transition metal (see figure), induced by site‐selective C−Si cleavage in the ligand backbone by means of NaN3, is reported. The carbanionic methine fragment generated in situ displaces phosphorus as donor to the RhI center with formation of a highly strained four‐membered Rh‐N‐C‐C metallacycle, stabilized by dimerization involving phosphane coordination to the neighboring rhodium center.