Coupled chemo(enzymatic) reactions in continuous flow

• Ruslan Yuryev,
• Simon Strompen and
• Andreas Liese

Beilstein J. Org. Chem. 2011, 7, 1449–1467, doi:10.3762/bjoc.7.169

• immobilized Candida antarctica lipase B (Novozym 435) was used as a heterogeneous catalyst in the kinetic resolution of the alcohol 22 [30]. Racemization of the unreacted (S)-22 was achieved with acidic zeolite catalysts. Both heterogenous catalysts were coated with ionic liquids for improved stability of the

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• primary amines is an important reaction in organic synthesis. He et al. developed an efficient gold-catalyzed one-pot selective N-alkylation of amines with alcohols [57]. In their study, gold nanoparticles supported on titania act as an efficient heterogeneous catalyst for the reaction to give the N

Air-stable, recyclable, and time-efficient diphenylphosphinite cellulose-supported palladium nanoparticles as a catalyst for Suzuki–Miyaura reactions

• Qingwei Du and
• Yiqun Li

Beilstein J. Org. Chem. 2011, 7, 378–385, doi:10.3762/bjoc.7.48

• Qingwei Du Yiqun Li Department of Chemistry, Jinan University, 510632 Guangzhou, China 10.3762/bjoc.7.48 Abstract A diphenylphosphinite cellulose palladium complex (Cell–OPPh2–Pd0) was found to be a highly efficient heterogeneous catalyst for the Suzuki–Miyaura reaction. The products were

C-Arylation reactions catalyzed by CuO-nanoparticles under ligand free conditions

• Mazaahir Kidwai,
• Saurav Bhardwaj and
• Roona Poddar

Beilstein J. Org. Chem. 2010, 6, No. 35, doi:10.3762/bjoc.6.35

• Mazaahir Kidwai Saurav Bhardwaj Roona Poddar Green Research Laboratory, Department ofChemistry, University of Delhi, Delhi, India 110007 10.3762/bjoc.6.35 Abstract CuO-nanoparticles were found to be an excellent heterogeneous catalyst for C-arylation of active methylene compounds using various

• aryl halides. The products were obtained in good to excellent yield. The catalyst can be recovered and reused for four cycles with almost no loss in activity. Keywords: active methylene compounds; C-arylation; heterogeneous catalyst; recyclability; Introduction Carbon-carbon (C–C) bond formation is

• catalysts in organic reactions [31][32][33], we now report the synthesis of 3-arylpentane-2,4-diones and diethyl 2-aryl-malonates using CuO-nanoparticles as a heterogeneous catalyst. Results and Discussion The reaction was carried out several times in order to establish the optimum ratio of reactants

Flow through reactors for organic chemistry: directly electrically heated tubular mini reactors as an enabling technology for organic synthesis

• Ulrich Kunz and
• Thomas Turek

Beilstein J. Org. Chem. 2009, 5, No. 70, doi:10.3762/bjoc.5.70

• temperature profile cannot be reached by traditional heating methods in an easy way. Kinetic measurements The applicability for kinetic measurements is demonstrated using a simple organic model reaction. We chose the hydrolysis of methyl formate with an ion exchange resin as an acidic heterogeneous catalyst

Hydroxyapatite supported caesium carbonate as a new recyclable solid base catalyst for the Knoevenagel condensation in water

• Monika Gupta,
• Rajive Gupta and
• Medha Anand

Beilstein J. Org. Chem. 2009, 5, No. 68, doi:10.3762/bjoc.5.68

• that the catalysis is purely heterogeneous. Similarly, the reaction between 4-methoxybenzaldehyde and malonic acid was also carried out to investigate heterogeneity. The second point is the recyclability and deactivation of the heterogeneous catalyst which are equally important when supported catalysts

Continuous flow enantioselective arylation of aldehydes with ArZnEt using triarylboroxins as the ultimate source of aryl groups

• Julien Rolland,
• Xacobe C. Cambeiro,
• Carles Rodríguez-Escrich and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2009, 5, No. 56, doi:10.3762/bjoc.5.56

• enantioselectivity (entry 6). It is interesting to note that, although enantioselectivities were not as high as those obtained with the homogeneous catalyst 1 under batch conditions with the same arylating agents [30], or even with the heterogeneous catalyst 2 used under batch conditions with PhZnEt generated from

From discovery to production: Scale- out of continuous flow meso reactors

• Peter Styring and
• Ana I. R. Parracho

Beilstein J. Org. Chem. 2009, 5, No. 29, doi:10.3762/bjoc.5.29

• ][10]. Such materials show the beneficial properties of homogeneous catalysts (activity and selectivity) as well as those of a heterogeneous catalyst (robust and re-usable). These materials have been termed ‘androgynous’ due to these dichotomous properties [8]. The palladium catalysts are active in the

• catalyst was detected over the course of the cycles and ICP-ES studies showed the nickel content in the resin was the same as when the catalyst was initially prepared. An important point of concern when using heterogeneous catalyst is its lifetime, particularly for industrial and pharmaceutical

Zeolite catalyzed solvent- free one-pot synthesis of dihydropyrimidin- 2(1H)-ones – A practical synthesis of monastrol

• Mukund G. Kulkarni,
• Sanjay W. Chavhan,
• Mahadev P. Shinde,
• Dnyaneshwar D. Gaikwad,
• Ajit S. Borhade,
• Attrimuni P. Dhondge,
• Yunnus B. Shaikh,
• Vijay B. Ningdale,
• Mayur P. Desai and
• Deekshaputra R. Birhade

Beilstein J. Org. Chem. 2009, 5, No. 4, doi:10.3762/bjoc.5.4

• under solvent-free conditions. The well-known titanium silicate TS-1 (also known as titanium silicalite) [42] is a widely used heterogeneous catalyst. Therefore we decided to explore its suitability in the Biginelli reaction. For this purpose, a mixture of an aldehyde 1 (1 mmol), ethyl acetoacetate (2

Facile synthesis of two diastereomeric indolizidines corresponding to the postulated structure of alkaloid 5,9E- 259B from a Bufonid toad (Melanophryniscus)

• Angela Nelson,
• H. Martin Garraffo,
• Thomas F. Spande,
• John W. Daly and
• Paul J. Stevenson

Beilstein J. Org. Chem. 2008, 4, No. 6, doi:10.1186/1860-5397-4-6

• at about δ 3.27 ppm. Reduction of the alkene 5 with hydrogen and a heterogeneous catalyst gave the product indolizidines as a mixture of C8 diastereoisomers. When platinum oxide was used as catalyst, a 1:1 mixture of diastereoisomers resulted, but when platinum-on-carbon was employed, a 4:1 mixture

Development of potential manufacturing routes for substituted thiophenes – Preparation of halogenated 2-thiophenecarboxylic acid derivatives as building blocks for a new family of 2,6-dihaloaryl 1,2,4-triazole insecticides

• John W. Hull Jr.,
• Duane R. Romer,
• David E. Podhorez,
• Mezzie L. Ash and
• Christine H. Brady

Beilstein J. Org. Chem. 2007, 3, No. 23, doi:10.1186/1860-5397-3-23

• rates were found to be slower for the heterogeneous catalyst compared to homogeneous palladium acetate. The use of DPPP was required for successful conversion to carbonylation product, even with the use of heterogeneous Pd/C catalyst. Carbonylation of 8 in an Et3N/H2O solvent system gave acid 19, while

Hydrogenation of aromatic ketones, aldehydes, and epoxides with hydrogen and Pd(0)EnCat™ 30NP

• Steven V. Ley,
• Angus J. P. Stewart-Liddon,
• David Pears,
• Remedios H. Perni and
• Kevin Treacher

Beilstein J. Org. Chem. 2006, 2, No. 15, doi:10.1186/1860-5397-2-15

• hydrides (NaBH4, LiAlH4) and their derivatives, in addition to borane and substituted boranes, which are the most commonly used. [1][2][3][4] However, from a practical point of view a more attractive approach is to develop a selective heterogeneous catalyst that is efficient for this transformation. From