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Self‐Assembled, Highly Positively Charged, Allyl–Pd Crowns: Cavity‐Pocket‐Driven Interactions of Fluoroanions
Author(s) -
Ferrer Montserrat,
Gallen Albert,
Gutiérrez Albert,
Martínez Manuel,
Ruiz Eliseo,
Lorenz Yvonne,
Engeser Marianne
Publication year - 2020
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202000316
Subject(s) - cationic polymerization , selectivity , chemistry , allylic rearrangement , molar ratio , catalysis , benzene , ion , crystallography , tsuji–trost reaction , medicinal chemistry , nmr spectra database , stereochemistry , spectral line , polymer chemistry , organic chemistry , physics , astronomy
A series of dodecanuclear highly positively charged homo‐ and heterometallamacrocycles [{Pd(η 3 ‐2‐Me‐C 3 H 4 )} 6 (4‐PPh 2 py) 12 {M 2 (tpbz)} 3 ] 18+ (M=Pd, Pt; tpbz=1,2,4,5‐tetrakis(diphenylphosphanyl)benzene were synthesized by the quantitative self‐assembly of {Pd(η 3 ‐2‐Me‐C 3 H 4 )} + , {M 2 (tpbz)} 4+ and 4‐PPh 2 py moieties in 2:1:4 molar ratio. The cationic assemblies were obtained as salts of different fluorinated anions with diverse sizes and electronic properties, namely BF 4 − , PF 6 − , SbF 6 − and CF 3 SO 3 − . The new crown‐like metallamacrocycles showed remarkable differences in their NMR spectra due to the presence of the different counteranions. On the basis of the observed variations, the metallacycles have been tested as catalytic precursors in allylic alkylation reactions. The anion‐dependent activity and selectivity has been analysed and compared with that of the corresponding monometallic allylic corners [Pd(η 3 ‐2‐Me‐C 3 H 4 )(4‐PPh 2 py) 2 ]X (X=BF 4 − , PF 6 − , SbF 6 − , CF 3 SO 3 − ). DFT calculations have been employed in order to help to the interpretation of the experimental data and to model the anion–crown interactions.