Dehydrogenative Heck Reaction of Furans and Thiophenes with Styrenes under Mild Conditions and Influence of the Oxidizing Agent on the Reaction Rate

Abstract

In this study, the kinetics of the acid catalyzed hydrolysis of microcrystalline cellulose (Avicel PH101) to levulinic (LA) and formic (FA) acids was investigated in a batch reactor over the following range of conditions: 160–200°C, hydrochloric acid concentrations of 0.309–0.927 M (11.3–33.8 g/l), cellulose concentrations of 49.8–149 mM (8.06–24.1 g/l), and residence times of 0–50 min. The maximum LA yield of around 60% of theoretical was achieved for an initial cellulose concentration of 99.6 mM, acid concentration 0.927 M, and 180–200°C. A mathematical model and its analytical solution were developed to predict conversion of cellulose to LA and FA through glucose and hydroxymethyl‐2‐furfural based on an irreversible pseudo‐first order reaction. Rate analysis of each reaction indicated that the rate‐controlling step shifted from LA formation initially to HMF formation later. © 2011 American Institute of Chemical Engineers AIChE J, 2012

Palladium-Catalyzed Intermolecular Oxidative Amination of Alkenes with Amines, Using Molecular Oxygen as Terminal Oxidant

“…functional groups directly connected to the C=C bonds of olefins [4][5][6][7][8][9]. Oxidative coupling for the formation of nitrogen-containing compounds such as enamines using metal-catalyzed oxidative amination of olefins by dioxygen, known as the aza-Wacker reaction, has been the subject of considerable research [10][11][12][13][14][15][16][17][18].…”

“…Needless to say, when the reaction was conducted under an Ar atmosphere, a low yield of 13 (3%) was observed, indicating that the oxygen in the air serves as the sole oxidant. (6) Under the optimized conditions, various primary anilines and electron-deficient olefins were tolerated in the oxidative amination (Scheme 7). As mentioned above, the use of ortho-substituted anilines such as o-toluidine, o-isopropylaniline, and o-anisidine gave high yields (71-81%) of the corresponding enamines, with high levels of regio-and stereo-selectivity (E:Z = 1:>20).…”

Solvent‐Free Ruthenium(II)‐Catalyzed C–H Activation: Synthesis of Alkenylarylpyrazole Derivatives

“…However, the oxidative alkenylation of heteroarenes is named the Moritani-Fujiwara reaction. [8,9] In this regard, different palladium [10][11][12][13] and rhodium catalysts [14][15][16] have already been used to promote the oxidative alkenylation of heteroarenes with a variety of directing groups, namely, imines, [17,18] amines, [19] and carboxylates. [20,21] Rutheniumcatalyst-directed arylation of unactivated C-H bonds with phenols was reported by Ackermann.…”

Cross‐Coupling Arylations: Precedents and Rapid HistoricalReview of the Field

“…In 2011, Jean Le Bras's team [87] reported a very mild Pd-catalyzed dehydrogenative Heck-Mizoroki reaction of furans and thiophenes with styrenes at room temperature (Scheme 1.32)! Pd(OAc) 2 was used as the catalyst with benzoquinone (BQ) as the oxidizing agent.…”