A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

• Santanu Hati,
• Ulrike Holzgrabe and
• Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

• acceptor) or via oxidative dehydrogenation in the presence of appropriate oxidants. In absence of hydrogen acceptors, post dehydrogenation the hydrogen is released as H2↑. Catalysts such as iridium pincer complexes, CuAl2O3, hydroxyapatite bound palladium and ruthenium hydride complexes have been harnessed

Synthesis of medronic acid monoesters and their purification by high-performance countercurrent chromatography or by hydroxyapatite

• Elina Puljula,
• Jouko Vepsäläinen and
• Petri A. Turhanen

Beilstein J. Org. Chem. 2016, 12, 2145–2149, doi:10.3762/bjoc.12.204

• monoalkyl esters of medronic acid. Two methods were developed for the purification of medronic acid monoesters: 1) small scale (10–20 mg) purification by using hydroxyapatite and 2) large scale (tested up to 140 mg) purification by high-performance countercurrent chromatography (HPCCC). Keywords

• : bisphosphonate; bisphosphonate monoester; high performance counter current chromatography; hydroxyapatite; medronic acid; Introduction Bisphosphonates (BPs) have been used for decades in the treatment of bone-related diseases as well as for bone imaging. Nevertheless, several recent reports have demonstrated

• mixed tetraesters as the starting material for the synthesis of more important monoesters of medronic acid and a simple HPCCC-based method for the purification of the prepared monoesters. In addition, a small-scale purification method for medronic acid monoesters by using hydroxyapatite is introduced

Preparation of mixed trialkyl alkylcarbonate derivatives of etidronic acid via an unusual route

• Petri A. Turhanen,
• Janne Weisell and
• Jouko J. Vepsäläinen

Beilstein J. Org. Chem. 2012, 8, 2019–2024, doi:10.3762/bjoc.8.228

• water softeners by inhibiting the crystallization of calcium salts, but today the basis for their main use is their high affinity for the bone mineral hydroxyapatite. Since they are effective inhibitors of bone resorption, BPs are used for the treatment of various bone diseases and disorders of calcium

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

• Imines and oximes are versatile synthetic intermediates for the preparation of dyes, pharmaceuticals, and agricultural chemicals. Sun et al. have reported a multi-task Au/hydroxyapatite reagent for the heterogeneous catalyzed oxidation of alcohols and amines to imines or oximes [56]. N-alkylation of

ROMP-Derived cyclooctene-based monolithic polymeric materials reinforced with inorganic nanoparticles for applications in tissue engineering

• Franziska Weichelt,
• Solvig Lenz,
• Stefanie Tiede,
• Ingrid Reinhardt,
• Bernhard Frerich and
• Michael R. Buchmeiser

Beilstein J. Org. Chem. 2010, 6, 1199–1205, doi:10.3762/bjoc.6.137

• two types of inorganic nanoparticles (i.e., CaCO3 and calcium hydroxyapatite, respectively) using the third-generation Grubbs initiator RuCl2(Py)2(IMesH2)(CHPh). The physico-chemical properties of the monolithic materials, such as pore size distribution and microhardness were studied with regard to

• materials are required [7][8][9][10][11][12]. Bone is a natural composite material, being composed of an inorganic compound (calcium hydroxyapatite) incorporated into an organic matrix (collagen) and thus resulting in a material, which possesses high stiffness and fracture toughness [13][14]. Ring-opening

• scaffold materials in TE with specific properties, e.g., high mechanical strength and biocompatibility, we report here ROMP-derived cyclooctene-based monoliths reinforced with two of the most frequently used inorganic materials in nature, i.e., calcite and calcium hydroxyapatite [19], respectively. Results

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

• Daniel Crespy and
• Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

• hydroxyapatite on the surface of the particles. Methyl methacrylate, butyl acrylate, and acrylic acid were copolymerized in the presence of alkyd resins to yield hybrid latexes [39]. Similar copolymerizations were carried out with styrene, tetraethylene glycol diacrylate as crosslinker, and up to 20 mol % of 2

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

• Monika Gupta Rajive Gupta Medha Anand Department of Chemistry, University of Jammu, Jammu 180 006, India 10.3762/bjoc.5.68 Abstract The Knoevenagel condensation between aromatic aldehydes and malononitrile, ethyl cyanoacetate or malonic acid with hydroxyapatite supported caesium carbonate in

• water is described. HAP–Cs2CO3 was found to be a highly active, stable and recyclable catalyst under the reaction conditions. Keywords: ethyl cyanoacetate; hydroxyapatite supported caesium carbonate; Knoevenagel condensation; malonic acid; malononitrile; Introduction An area of recent intense

• of the desired product over traditional homogeneous systems – is a pivotal process in organic synthesis. Diverse ranges of heterogeneous solid supports have been employed so far. Recently, hydroxyapatite has proved to be a highly efficient catalyst due to its promising ability as a macro-ligand for