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Phosphines with N‐Heterocyclic Boryl‐Substituents: Ligands for Coordination Chemistry and Catalysis
Author(s) -
Kaaz Manuel,
Locke Ralf J. C.,
Merz Luisa,
Benedikter Mathis,
König Simon,
Bender Johannes,
Schlindwein Simon H.,
Nieger Martin,
Gudat Dietrich
Publication year - 2019
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201801081
Subject(s) - chemistry , steric effects , amination , substituent , phosphine , catalysis , bromobenzene , medicinal chemistry , coordination complex , organometallic chemistry , aryl , hydroamination , stereochemistry , organic chemistry , metal , alkyl
Boryl‐substituted phosphines NHB–P(R)Ph (R = H, Ph, NHB = N‐heterocyclic boryl substituent) react with Fe 2 (CO) 9 to give isolable Fe(CO) 4 complexes, two of which were characterized by single‐crystal XRD studies. The electronic and steric properties for a series of the boryl phosphines were further assessed by evaluation of TEPs for in‐situ formed complexes [RhCl(NHB–PR 1 R 2 )(CO) 2 ] (R 1 , R 2 = H, Ph, Me, NMe 2 ), and calculations of buried volumes for Fe(CO) 4 complexes. The results imply that the NHB‐phosphines exhibit due to their conformational flexibility some variability in their steric bulk, and that some specimens may exhibit similar electron releasing power and steric demand as t Bu 3 P. Studies of the amination of bromobenzene with 2,6‐diisopropylaniline confirmed that these properties can be exploited to promote Pd‐catalyzed C–N cross coupling reactions, and that formal replacement of a phenyl by a NHB substituent in the auxiliary phosphine has a beneficial effect on catalyst performance.