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Pyrrole‐based pincer ligands containing iminophosphorane moieties and their coordination chemistry with group 1 metals and magnesium
Author(s) -
Ehrlich Nico,
Freytag Matthias,
Raeder Jan,
Jones Peter G.,
Walter Marc D.
Publication year - 2021
Publication title -
zeitschrift für anorganische und allgemeine chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.354
H-Index - 66
eISSN - 1521-3749
pISSN - 0044-2313
DOI - 10.1002/zaac.202100080
Subject(s) - chemistry , deprotonation , trimethylsilyl , medicinal chemistry , ligand (biochemistry) , methylene , coordination complex , pyrrole , magnesium , alkali metal , yield (engineering) , lithium (medication) , metal , alkyl , stereochemistry , ion , organic chemistry , medicine , biochemistry , materials science , receptor , metallurgy , endocrinology
The Staudinger reaction of 2,5‐bis((di‐ tert ‐butylphosphaneyl)methyl)‐1 H ‐pyrrole ( t Bu PNP)H; t Bu PNP=C 4 H 2 N‐2,5‐CH 2 P t Bu 2 ) with 2 equiv. of Me 3 SiN 3 cleanly furnishes 1,1′‐((1 H ‐pyrrole‐2,5‐diyl)bis(methylene))bis(1,1‐di‐ tert ‐butyl‐ N ‐(trimethylsilyl)‐λ 5 ‐phosphanimine) ( 1 ; (NPNPN)H, NPNPN=C 4 H 2 N‐2,5‐CH 2 P t Bu 2 NSiMe 3 ) in excellent yield. Pyrrole 1 is easily deprotonated by alkali metal amides, [MN(SiMe 3 ) 2 ] (M=Li, Na, K, Cs) to yield the corresponding alkali metal pyrrolides, 1‐M . Compound 1‐Li is features a κ‐ N , N , N coordination whereby both iminophosphorane side‐arms are coordinated to the lithium cation (with additional short Li⋅⋅⋅H contacts, whereas the heavier congeners form dimeric structures. This results in κ‐N,N coordination within one [(NPNPN)M] (M=Na, Cs) unit, and the dimeric structure is then completed by additional η 5 ‐coordination of the pyrrolyl ligand to the neighbouring alkali metal. Furthermore, heteroleptic magnesium alkyl complexes, 1‐MgR , are isolated from the reaction of [MgR 2 ] (R= CH 2 SiMe 3 , CH 2 CMe 3 , CH 2 CMe 2 Ph) with (PNP*)H (1 equiv).