Rationally designed pincer-type Heck catalysts bearing aminophosphine substituents : PdIV intermediates and palladium nanoparticles

Bolliger, Jeanne L.; Blacque, Olivier; Frech, Christian M.

doi:10.1002/chem.200800441

Publication type:	Article in scientific journal
Type of review:	Peer review (publication)
Title:	Rationally designed pincer-type Heck catalysts bearing aminophosphine substituents : PdIV intermediates and palladium nanoparticles
Authors:	Bolliger, Jeanne L. Blacque, Olivier Frech, Christian M.
DOI:	10.1002/chem.200800441
Published in:	Chemistry - A European Journal
Volume(Issue):	14
Issue:	26
Page(s):	7969
Pages to:	7977
Issue Date:	2008
Publisher / Ed. Institution:	Wiley
ISSN:	0947-6539 1521-3765
Language:	English
Subject (DDC):	540: Chemistry
Abstract:	The aminophosphine-based pincer complexes [C6H3-2,6-(XP(piperidinyl)2)2Pd(Cl)] (X=NH 1; X=O 2) are readily prepared from cheap starting materials by sequential addition of 1,1',1''-phosphinetriyltripiperidine and 1,3-diaminobenzene or resorcinol to solutions of [Pd(cod)(Cl)2] (cod=cyclooctadiene) in toluene under N2 in "one pot". Compounds 1 and 2 proved to be excellent Heck catalysts and allow the quantitative coupling of several electronically deactivated and sterically hindered aryl bromides with various olefins as coupling partners at 140 degrees C within very short reaction times and low catalyst loadings. Increased reaction temperatures also enable the efficient coupling of olefins with electronically deactivated and sterically hindered aryl chlorides in the presence of only 0.01 mol % of catalyst. The mechanistic studies performed rule out that homogeneous Pd 0 complexes are the catalytically active forms of 1 and 2. On the other hand, the involvement of palladium nanoparticles in the catalytic cycle received strong experimental support. Even though pincer-type Pd IV intermediates derived from 1 (and 2) are not involved in the catalytic cycle of the Heck reaction, their general existence as reactive intermediates (for example, in other reactions) cannot be excluded. On the contrary, they were shown to be thermally accessible. Compounds 1 and 2 show a smooth halide exchange with bromobenzene to yield their bromo derivatives in DMF at 100 degrees C. Experimental observations revealed that the halide exchange most probably proceeded via pincer-type Pd IV intermediates. DFT calculations support this hypothesis and indicated that aminophosphine-based pincer-type Pd IV intermediates are generally to be considered as reactive intermediates in reactions with aryl halides performed at elevated temperatures.
URI:	https://digitalcollection.zhaw.ch/handle/11475/10510
Fulltext version:	Published version
License (according to publishing contract):	Licence according to publishing contract
Departement:	Life Sciences and Facility Management
Appears in collections:	Publikationen Life Sciences und Facility Management

Files in This Item:

There are no files associated with this item.

Show full item record

Bolliger, J. L., Blacque, O., & Frech, Christian M. (2008). Rationally designed pincer-type Heck catalysts bearing aminophosphine substituents : PdIV intermediates and palladium nanoparticles. Chemistry - A European Journal, 14(26), 7969–7977. https://doi.org/10.1002/chem.200800441

Bolliger, J.L., Blacque, O. and Frech, Christian M. (2008) ‘Rationally designed pincer-type Heck catalysts bearing aminophosphine substituents : PdIV intermediates and palladium nanoparticles’, Chemistry - A European Journal, 14(26), pp. 7969–7977. Available at: https://doi.org/10.1002/chem.200800441.

J. L. Bolliger, O. Blacque, and Christian M. Frech, “Rationally designed pincer-type Heck catalysts bearing aminophosphine substituents : PdIV intermediates and palladium nanoparticles,” Chemistry - A European Journal, vol. 14, no. 26, pp. 7969–7977, 2008, doi: 10.1002/chem.200800441.

BOLLIGER, Jeanne L., Olivier BLACQUE und Christian M. FRECH, 2008. Rationally designed pincer-type Heck catalysts bearing aminophosphine substituents : PdIV intermediates and palladium nanoparticles. Chemistry - A European Journal. 2008. Bd. 14, Nr. 26, S. 7969–7977. DOI 10.1002/chem.200800441

Bolliger, Jeanne L., Olivier Blacque, and Christian M. Frech. 2008. “Rationally Designed Pincer-Type Heck Catalysts Bearing Aminophosphine Substituents : PdIV Intermediates and Palladium Nanoparticles.” Chemistry - A European Journal 14 (26): 7969–77. https://doi.org/10.1002/chem.200800441.

Bolliger, Jeanne L., et al. “Rationally Designed Pincer-Type Heck Catalysts Bearing Aminophosphine Substituents : PdIV Intermediates and Palladium Nanoparticles.” Chemistry - A European Journal, vol. 14, no. 26, 2008, pp. 7969–77, https://doi.org/10.1002/chem.200800441.