In Situ Generated Palladium on Aluminum Phosphate as Catalytic System for the Preparation of β,β-Diarylated Olefins by Matsuda–Heck Reaction

Abstract

In situ generated palladium on aluminum phosphate provides a novel and active catalytic system for the preparation of β,β-diarylated olefins using the Matsuda–Heck reaction. The reaction conditions of this catalytic protocol were optimized by a Response-Surface model.

Benign Arylations of Dimethyl Itaconate via Heck–Matsuda Reaction Utilizing in‐Situ Generated Palladium on Aluminum Oxide

“…Stimulated by the work of Correia and co‐workers concerning the biarylation of acrylates and maleic anhydride, the iterative Heck–Matsuda couplings with itaconimides by B. Schmidt et al and encouraged by our studies regarding the β,β‐diarylation of acrylates and vinylphosphonates we decided to embark on the biarylation of dimethyl iatconate. In accordance with our previous reaction conditions regarding the β,β‐diarylation of acrylates with palladium on aluminum phosphate as catalyst, we converted several diazonium salts (2.2 equiv.)…”

“…In accordance with our previous reaction conditions regarding the β,β‐diarylation of acrylates with palladium on aluminum phosphate as catalyst, we converted several diazonium salts (2.2 equiv.) with dimethyl itaconate at 40 °C and 2 mol‐% catalyst . In the context of this study both electron‐rich and electron‐poor aryldiazonium salts were investigated (Table ).…”

Utilization of Synthetic Calcium‐Phyllosilicates as Bifunctional Bases in the Matsuda‐Heck Reaction

“…Furthermore, the development of efficient supported palladium catalysts is one of the most attractive targets of actual research activities because of an easier metal recovery combined with a lower contamination of the products by toxic palladium residues and a high reactivity as well as stability . For this reason a broad range of supporting materials were utilized in the Matsuda‐Heck reaction …”

“…[10] For this reason a broad range of supporting materials were utilized in the Matsuda-Heck reaction. [11][12][13] In the case of Pd/CaCO 3 as bifunctional catalyst it has to be stated that the evolving tetrafluoroboric acid is dissolving the calcium carbonate as consequence of the neutralization reaction. Thus, a negative impact on the reactivity of the catalytic system as a consequence of the loss of calcium carbonate as supporting material has to be considered.…”

Iterative Arylation of Itaconimides with Diazonium Salts through Electrophilic Palladium Catalysis: Divergent β-H-Elimination Pathways in Repetitive Matsuda–Heck Reactions

“…Although several modifications and improvements, including a catalytic variant, 18 have been published since the original report, 6,[19][20][21][22][23] some disadvantages of this approach remain: in general, elevated temperatures and protic solvents are required to achieve useful levels of conversion, which may affect hydrolytic stability of the succinimide structure; 24 the required benzaldehydes are sometimes prone to oxidation and need to be purified beforehand; other carbonyl groups that may also undergo Wittig olefination reactions are not tolerated; the inevitable formation of stoichiometric amounts of phosphine oxides can hamper product isolation and purification if the 3-arylmethylidene pyrrolidine-2,5-diones have similar polarity. In continuation of our previous investigations [25][26][27] into the development and application of Matsuda-Heck reactions, 28 i. e. the Pd-catalyzed Heck-type coupling of arene diazonium salts with alkenes, [29][30][31][32][33][34][35][36] we wondered whether an alternative approach to 3-arylmethylidene pyrrolidine-2,5-diones exo-1 that starts from itaconimides 5 and stable and isolable arene diazonium salts 6 might be a competitive or even advantageous alternative to the phospha-Michael-addition / Wittig-olefination approach. Important questions to be answered in this context are: will the final -H-elimination step 36 leading to the liberation of the coupling products proceed exo-or endo-selectively (i. e. to exo-1 or to endo-1), or to a mixture of exoand endo-isomers?…”