N-Heterocyclic carbene-catalyzed direct cross-aza-benzoin reaction: Efficient synthesis of α-amino-β-keto esters

• Takuya Uno,
• Yusuke Kobayashi and
• Yoshiji Takemoto

Beilstein J. Org. Chem. 2012, 8, 1499–1504, doi:10.3762/bjoc.8.169

• of PhI=O is needed as the oxidant (Figure 1, (e)) [23]. Therefore, mild, efficient and environmentally friendly strategies for the synthesis of these esters are still needed. We envisioned that highly atom-efficient synthesis of α-amino-β-keto esters could be achieved by a novel umpolung approach

Recent advances towards azobenzene-based light-driven real-time information-transmitting materials

• Jaume García-Amorós and
• Dolores Velasco

Beilstein J. Org. Chem. 2012, 8, 1003–1017, doi:10.3762/bjoc.8.113

• information beyond the time scale of microseconds, as well as to produce molecular materials with high oscillation frequencies in their optical properties. In addition, the possible design of such materials in such a way that they would be soluble in water (an environmentally friendly solvent) could be a

Enantioselective Michael addition of 2-hydroxy-1,4-naphthoquinones to nitroalkenes catalyzed by binaphthyl-derived organocatalysts

• Saet Byeol Woo and
• Dae Young Kim

Beilstein J. Org. Chem. 2012, 8, 699–704, doi:10.3762/bjoc.8.78

• synthesis [12], and intensive research efforts have been directed toward the development of enantioselective catalytic protocols for this reaction [13][14][15]. The organocatalyst-mediated enantioselective conjugate addition reactions, which are both powerful and environmentally friendly, have been

Syntheses and applications of furanyl-functionalised 2,2’:6’,2’’-terpyridines

• Jérôme Husson and
• Michael Knorr

Beilstein J. Org. Chem. 2012, 8, 379–389, doi:10.3762/bjoc.8.41

• context of a more environmentally friendly and “greener” chemistry, an adaptation of this well-established method was proposed with the aim of reducing the solvent use [16][17][18]. Namely, two equivalents of neat 2-acetylpyridine (4) were reacted with one equivalent of an aldehyde in the presence of

Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

• Xacobe C. Cambeiro,
• Rafael Martín-Rapún,
• Pedro O. Miranda,
• Sonia Sayalero,
• Esther Alza,
• Patricia Llanes and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2011, 7, 1486–1493, doi:10.3762/bjoc.7.172

• organocatalyzed α-aminoxylation of aldehydes and ketones experienced in the last few years has transformed it into a powerful, reliable and environmentally friendly method for the synthesis of α-hydroxyaldehydes and ketones [32][33][34]. Despite its extreme simplicity and very high enantiocontrol, organocatalysis

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

• renewable resources and which is actively propagated presently in view of the forthcoming global energy crisis. Another example of a biorefinery process is the production of hydrogen, i.e., the most environmentally friendly fuel. Oh and coworkers realized a continuous anaerobic fermentation of Clostridium

Efficient and selective chemical transformations under flow conditions: The combination of supported catalysts and supercritical fluids

• M. Isabel Burguete,
• Eduardo García-Verdugo and
• Santiago V. Luis

Beilstein J. Org. Chem. 2011, 7, 1347–1359, doi:10.3762/bjoc.7.159

• given process as being more environmentally friendly than the corresponding one run in an organic solvent, the whole process should be evaluated (“cradle-to-grave” evaluation), including an assessment of the energy consumption. Such studies are out of the scope of this paper but they should be kept in

PEG-embedded KBr₃: A recyclable catalyst for multicomponent coupling reaction for the efficient synthesis of functionalized piperidines

• Sanny Verma,
• Suman L. Jain and
• Bir Sain

Beilstein J. Org. Chem. 2011, 7, 1334–1341, doi:10.3762/bjoc.7.157

• that it is more environmentally friendly [4][5][8][9]. Among the various known multicomponent reactions, the MCRs that involve 1,3-dicarbonyl compounds, aldehydes, and nucleophilic compounds have received particular interest in recent years owing to their potential to provide different condensation

Reductive amination with zinc powder in aqueous media

• Giovanni B. Giovenzana,
• Daniela Imperio,
• Andrea Penoni and
• Giovanni Palmisano

Beilstein J. Org. Chem. 2011, 7, 1095–1099, doi:10.3762/bjoc.7.125

• and 1-aminoadamantane) did not react; iii) aminoesters reacted giving low yields of the corresponding carboxylic acid derivative (ester hydrolysis occurring even with tert-butyl esters). Conclusion In summary, zinc dust in 5% aqueous KOH solution was found to be an environmentally friendly alternative

Achiral bis-imine in combination with CoCl₂: A remarkable effect on enantioselectivity of lipase-mediated acetylation of racemic secondary alcohol

• K. Arunkumar,
• M. Appi Reddy,
• T. Sravan Kumar,
• B. Vijaya Kumar,
• K. B. Chandrasekhar,
• P. Rajender Kumar and
• Manojit Pal

Beilstein J. Org. Chem. 2010, 6, 1174–1179, doi:10.3762/bjoc.6.134

• the stereoselective synthesis of chiral molecules have increased enormously in recent years especially in the chemical and pharmaceutical industry [1]. Biocatalysis, being an environmentally friendly process, has attracted particular attention for this purpose [2][3][4][5][6]. For example, high

Solvent-free and time-efficient Suzuki–Miyaura reaction in a ball mill: the solid reagent system KF–Al₂O₃ under inspection

• Franziska Bernhardt,
• Ronald Trotzki,
• Tony Szuppa,
• Achim Stolle and
• Bernd Ondruschka

Beilstein J. Org. Chem. 2010, 6, No. 7, doi:10.3762/bjoc.6.7

• milling; C–C coupling; KF–Al2O3; palladium; solid reagent system; Introduction Over the last two decades, a major trend in the field of organic chemistry has been evident: environmentally friendly processes using safer reagents, generating fewer side products and requiring less use of solvents are in

A review of new developments in the Friedel–Crafts alkylation – From green chemistry to asymmetric catalysis

• Magnus Rueping and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2010, 6, No. 6, doi:10.3762/bjoc.6.6

• , intramolecular FC-type allylations are of great importance. One of the first intramolecular FC-type transformations using allyl alcohols was developed by Nishizawa et al. using Hg(OTf)2 as Lewis acid [89]. Since Hg(II) is not an environmentally friendly transition metal, Bandini et al. developed a “greener” Ag(I

Solvent-free phase-vanishing reactions with PTFE (Teflon^®) as a phase screen

• Kevin Pels and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2009, 5, No. 75, doi:10.3762/bjoc.5.75

• as a reagent or when insoluble products formed an impermeable barrier on the PTFE tape, this method was not suitable. Finally, PV-PTFE reaction design required use of a solvent. To address the described shortcomings and to make the design more environmentally friendly, we have developed solvent-free

An expedient and new synthesis of pyrrolo[1,2-b]pyridazine derivatives

• Rajeshwar Reddy Sagyam,
• Ravinder Buchikonda,
• Jaya Prakash Pitta,
• Himabindu Vurimidi,
• Pratap Reddy Padi and
• Mahesh Reddy Ghanta

Beilstein J. Org. Chem. 2009, 5, No. 66, doi:10.3762/bjoc.5.66

• derivatives 17a–j under similar conditions (Table 2). Conclusion In conclusion, a facile new approach has been developed for the synthesis of pyrrolo[1,2-b]pyridazine derivatives from commercially available and environmentally friendly chemicals. This newly developed method offers quick access to building

Asymmetric reactions in continuous flow

• Xiao Yin Mak,
• Paola Laurino and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

• compounds. Supported catalysts are in principle recoverable and, ideally, recyclable. With potential longer term usage, chemical processes can become more economically and environmentally friendly [16][17]. In conjunction with continuous flow, the reaction and separation of catalysts can be performed

• conditions as well as in supercritical carbon dioxide (scCO2), as means of creating a more ‘environmentally-friendly’ process [45]. Under the solventless or scCO2 flow conditions, the productivity of the catalyst was observed to be much higher. The use of supercritical fluids, in particular scCO2, as an

Silica- bound benzoyl chloride mediated the solid- phase synthesis of 4H-3,1-benzoxazin- 4-ones

• Kurosh Rad-Moghadam and
• Somayeh Rouhi

Beilstein J. Org. Chem. 2009, 5, No. 13, doi:10.3762/bjoc.5.13

• conditions by an economically viable and environmentally friendly method. Experimental Melting points were measured on an electrothermal apparatus and are uncorrected. IR spectra were obtained in KBr wafers on a Shimadzu IR-470 spectrometer. Chemicals were obtained from Merck (Darmstadt, Germany) and were

Phase- vanishing halolactonization of neat substrates

• Nicole Windmon and
• Veljko Dragojlovic

Beilstein J. Org. Chem. 2008, 4, No. 29, doi:10.3762/bjoc.4.29

• investigated phase-vanishing reaction conditions as a more efficient and an environmentally friendly alternative to traditional halolactonizations. Reactions were done on neat reagents, which avoided use of any solvent other then a phase screen – perfluorohexane (FC-72), simplified the work up and improved the

Microwave assisted synthesis of triazoloquinazolinones and benzimidazoquinazolinones

• Aboul-Fetouh E. Mourad,
• Ashraf A. Aly,
• Hassan H. Farag and
• Eman A. Beshr

Beilstein J. Org. Chem. 2007, 3, No. 11, doi:10.1186/1860-5397-3-11

• tool in organic synthesis, since by employing this technique it is generally possible to prepare organic compounds very fast, with high purity and better yields compared to other more conventional methods. [22][23][24] Additionally, in the search for economic and environmentally friendly synthetic