Palladacycles as Structurally Defined Catalysts for the Heck Olefination of Chloro‐ and Bromoarenes

Herrmann, Wolfgang A.; Broßmer, Christoph; Öfele, Karl; Reisinger, Claus‐Peter; Priermeier, Thomas; Beller, Matthias; Fischer, Hartmut

doi:10.1002/anie.199518441

Cited by 864 publications

(435 citation statements)

References 24 publications

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“…Fortyyears later, palladacycles are one of themost developed and studied classes of precatalysts because of their structural versatility and high catalytic activity [2,3]. Since the first report on the use of palladacycles for the coupling reactions by Herrmann in 1995 [4,5], awide variety of palladacycles have been successfully employed in these reactions. Among them,cyclopalladated complexes containing N-donor ferrocenylligand have been studied extensively in the past two decades [6,7].…”

Section: Discussionmentioning

confidence: 99%

Crystal structure of (5-bromo-2-pyridyl)ferrocene, C15H12BrFeN

Ma¹,

Wang²,

Li³

et al. 2012

Zeitschrift Für Kristallographie - New Crystal Structures

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Section: Discussionmentioning

confidence: 99%

Crystal structure of (5-bromo-2-pyridyl)ferrocene, C15H12BrFeN

Ma¹,

Wang²,

Li³

et al. 2012

Zeitschrift Für Kristallographie - New Crystal Structures

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“…For example, styrene and bromobenzene underwent complete C-C coupling in the presence of only 0.002 mol% of 2 and K 2 CO 3 within 2.5 h in DMF at 140 °C, whereas a reaction time of 10 h was necessary with catalyst 3 ( Table 2, entries 1 and 2). As demonstrated by the cross-coupling of styrene with the electronically deactivated 4-bromoanisole or the sterically hindered 2-bromotoluene, as well as the reaction of 4-methoxystyrene or 2-methylstyrene with bromobenzene, catalyst 2 offers two possible pathways to the same products, which are obtained in high yields and short reaction times by either way (Table 2, entries [5][6][7][8][9]. Although a decrease in activity was observed with 2-bromo-mxylene and styrene as substrates, nevertheless 95% conversion was obtained after 8 h (Table 2, entry 10).…”

Section: Heck Reactionmentioning

confidence: 99%

“…[4][5][6][7][8][9][10][11][12] Most of these palladium catalysts suffer from other drawbacks as well, such as poor thermal stability as well as poor stability towards oxygen and water, a major problem especially for catalysts employed in the Heck cross-coupling reaction because a typical protocol for this reaction still requires prolonged reaction times at high temperatures in combination with relatively high catalyst loadings -all factors promoting the formation of palladium black and thereby leading to inactivation of the active species.…”

Section: Introductionmentioning

confidence: 99%

Aminophosphine Palladium Pincer Complexes for Suzuki and Heck Reactions

Bolliger¹,

Frech²

2009

Chimia

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The aminophosphine-based pincer complexes [C6H3-2,6-{NHP(piperidinyl)2}2Pd(Cl)] (2) and [C6H3-2,6-{OP(piperidinyl)2}2Pd(Cl)] (3) 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 2 and 3 proved to be not only excellent catalysts for the Suzuki and the Heck cross-coupling reactions, but they are also very convenient to use: The toluene solutions of the 'one-pot' syntheses can be used directly for the catalytic reactions, thereby saving the time-consuming isolation of the catalysts. The Suzuki cross-coupling reaction catalyzed by 2 and 3 can be performed in air at 100 °C in toluene of technical quality: in the presence of only 0.001mol% of catalyst, several electronically deactivated and sterically hindered aryl bromides are quantitatively coupled with phenylboronic acid within a few minutes of reaction time. Furthermore, complex 2 enables the use of activated and non-activated aryl chlorides as coupling partners in the Suzuki reaction. Compounds 2 and 3 have also been shown to be highly active and reliable Heck catalysts: Very low catalyst loadings and short reaction times are required for the quantitative coupling of several electronically deactivated and sterically hindered aryl bromides with various olefins at 140 °C. At increased temperatures, even electronically deactivated and sterically hindered aryl chlorides can be efficiently coupled with olefins in the presence of only 0.01 mol% of catalyst. (3) 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 N 2 in 'one pot'. Compounds 2 and 3 proved to be not only excellent catalysts for the Suzuki and the Heck cross-coupling reactions, but they are also very convenient to use: The toluene solutions of the 'one-pot' syntheses can be used directly for the catalytic reactions, thereby saving the time-consuming isolation of the catalysts. The Suzuki cross-coupling reaction catalyzed by 2 and 3 can be performed in air at 100 °C in toluene of technical quality: in the presence of only 0.001mol% of catalyst, several electronically deactivated and sterically hindered aryl bromides are quantitatively coupled with phenylboronic acid within a few minutes of reaction time. Furthermore, complex 2 enables the use of activated and non-activated aryl chlorides as coupling partners in the Suzuki reaction. Compounds 2 and 3 have also been shown to be highly active and reliable Heck catalysts: Very low catalyst loadings and short reaction times are required for the quantitative coupling of several electronically deactivated and sterically hindered aryl bromides with various olefins at 140 °C. At increased temperatures, even electronically deactivated and sterically hindered aryl chlorides can be efficiently c...

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“…1,2 Pioneered by Herrmann and coworkers in 1995, 3 palladacyclic complexes have showcased extensive utility in prolific catalytic processes such as C-C crosscoupling 4,5 and allylic substitution, 6 and have more recently emerged as promising antimicrobial agents. 7 Traditional routes to palladacyclic scaffolds involve a metal-induced C-H activation process paralleled by coordination of pendant heteroatom donors (e.g.…”

mentioning

confidence: 99%

“…In light of such governing parameters, the majority of cyclometallated complexes are restricted to form via C(sp 2 )-H activation at an aromatic carbon (Figure 1 A), or C(sp 3 )-H activation at an aliphatic or benzylic carbon atom (Figure 1 B). 14,15 Whilst C(sp 3 )-H activation is a rapidly expanding field of research, the direct activation of non-acidic, non-aromatic sp 2 -hybridised C-H bonds is far less explored. Investigations in our laboratory focus on the reactivity and applications of Nheterocyclic carbenes (NHCs) as ancillary ligands for a broad scope of chemical transformations.…”

mentioning

confidence: 99%