Wednesday, 12 October 2016

From Box to Bench: Air-Stable Molybdenum Catalyst Tablets for Everyday Use in Olefin Metathesis

Molybdenum- and tungsten-based olefin metathesis catalysts have demonstrated excellent results in the control of cis (Z-) selectivity as well as enantioselectivity. However, their air and moisture sensitivity, which requires the use of a glovebox, has prevented their more widespread use by organic chemists. Now we report on developed, preweighed Mo catalysts formulated in paraffin tablets.

The significantly improved air stability, high homogeneity, and uniformity of the pellets allow researchers to carry out reactions on the bench avoiding the need of a glovebox.

The two different Mo-based complexes which were packed into tablets are XiMoPac-Mo001 (1) that can be used to achieve endo-selective enyne ring-closing metathesis (RCM) reactions, interalia; and XiMoPac-Mo003 (2) which was reported among the best catalysts to promote Z-selective cross-metathesis.

For the evaluation of the wax-protected catalysts commonly used, highly reproducible robust model reactions were chosen: homo cross-metathesis (HCM) of functionalized (e.g., methyl 9-decenoate) and unfunctionalized (allylbenzene) terminal olefins, and ring closing metathesis (RCM) of diethyl diallylmalonate. The yields and conversions were comparable with those which can be achieved in glovebox with nonformulated catalysts.

Exposure to air did not cause any significant reduction in conversion while the product selectivity (targeted product vs homologues derived from double bond isomerization) remained high. In contrast, exposure to air caused a measurable drop in the conversion with the nonprotected catalyst. Furthermore, the formulated catalysts remained unaffected even after 4 h of exposure to air, showing its enhanced air stability.

In conclusion, these commercially available air-stable Mo-catalyst tablets allow the reactions to be accomplished using ordinary Schlenk techniques, and hence simplify catalyst handling in pilot laboratories and plants.

From Box to Bench: Air-Stable Molybdenum Catalyst Tablets for Everyday Use in Olefin Metathesis

Levente Ondi*†, Gergely M. Nagy†, Janos B. Czirok†, Agota Bucsai†, and Georg E. Frater‡

† XiMo Hungary Ltd., 7. Zahony Str., Budapest HU-1031, Hungary

‡ XiMo AG, 3. Altsagenstrasse, Horw/Luzern CH-6048, Switzerland

Org. Process Res. Dev., Article ASAP

DOI: 10.1021/acs.oprd.6b00161

*Telephone: (36) 1 580 2202; Fax: (36) 1-580 2201; E-mail: levente.ondi@ximo-inc.com.

http://pubs.acs.org/doi/abs/10.1021/acs.oprd.6b00161

Levente Ondi

Director of R. & D. at XiMo Hungary Ltd.

https://hu.linkedin.com/in/levente-ondi-2005931a

Experience

Director of R&D

XiMo Hungary Ltd.

December 2012 – Present (3 years 11 months)

Head of Chemistry Lab.

XiMo Hungary Ltd.

December 2010 – December 2012 (2 years 1 month)

Senior Research Scientist

Servier Research Institute of Medicinal Chemistry

January 2008 – December 2010 (3 years)

Head of R&D Laboratory II.

Chemical Future Pharma Ltd.

June 2005 – December 2007 (2 years 7 months)

Research Scientist

Chemical Future Pharma Ltd.

March 1999 – August 2001 (2 years 6 months)

Education

Swiss Federal Institute of Technology Lausanne

Ph.D., Organometallic Chemistry

2001 – 2005

Budapesti Mûszaki és Gazdaságtudományi Egyetem / Technical University of Budapest

Master of Science (M.Sc.), Chemical Engineering

1993 – 1999

Ximo Hungary Kft.

Website

Directions

Chemical Plant

Address: Budapest, Záhony utca 7. D épület, 1031 Hungary

Prof. Dr. Georg Fráter

Chief Operating Officer

Over 30 years experience in the Swiss chemical industry
Over 20 years in the fragrance and flavor industry, five as Research Director for Givaudan
Former President Swiss Chemical Society (SCS)
Former Professor at the University of Zürich
Current member of the board of Thales Nano

Education: Ph.D. University of Zurich; M.Sc. University of Zurich

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Friday, 7 October 2016

What is Borrowing Hydrogen Catalysis?

A green chemistry approach to activating alcohols

Read more

read a full article...http://www.chemistryviews.org/details/education/9755121/What_is_Borrowing_Hydrogen_Catalysis.html

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Wednesday, 5 October 2016

A Rapid microwave assisted synthesis of novel 1,4-dihydropyridines derivatives under aqueous medium

July-August 2012, Volume 2, No.4

July-August 2012, Volume 2, No.4
Chemistry & Biology Interface, 2012, 2, 4, 206-257
(ISSN: 2249 – 4820)

A Rapid microwave assisted synthesis of novel 1,4-dihydropyridines derivatives under aqueous medium
Shailesh Thakrar, Dhairya Bhavsar, Vicky Jain, Anamik Shah

Chemistry & Biology Interface, 2012, 2, 4, 220-227 pg 220-227, Department of Chemistry, Saurashtra University, Rajkot-360005, India

[Full Text-PDF]

Keywords: 1, 4-dihydro pyridines, Pyrazole aldehyde, One-pot, Microwave, Aqueous medium,
Fe+3 montmorillonite clay K-10, HY-zeolite.
Abstract: An environment friendly synthesis of 1,4-dihydropyridine derivatives was developed by one pot multi component reaction of pyrazole aldehyde, EAA/MAA, 3-amino crotononitrile and Fe+3 montmorillonite clay K-10/ HY-zeolite under microwave irradiation in aqueous medium. The structures of all synthesized compounds were well characterized by Mass, FT-IR, 1H NMR and elemental analysis.

Methyl 5-cyano-1,4-dihydro-2,6-dimethyl- 4-(1,3-diphenyl-1H-pyrazol-4-yl)pyridine- 3-carboxylate (5a): MP: 182-184 oC; IR (cm-1): 3489, 3367, 3198, 2974, 2897, 2332, 2260, 1707, 1660, 1587, 1519, 1435, 1356, 1282, 744, 688. MS: m/z = 426.17; 1H NMR (DMSO-d6) δ ppm: 2.14(s, 6H), 2.58(s, 3H), 4.91(s, 1H), 6.91-6.99(d, 2H), 7.20-7.22(t, 2H), 7.29-7.31(t, 1H), 7.45-7.49(t, 2H), 7.60-7.62(d, 1H), 7.71-7.73(d, 2H), 7.95(s, 1H), 8.74(s, 1H). MS: m/z: 410.17; Anal. Calcd. for C25H22N4O2: C, 73.15; H, 5.40; N,13.65; O,7.80; Found: C, 73.06; H, 5.36; N, 13.61; O,7.79(%).

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Lewis acid-catalyzed 2-arylquinazoline formation from N′-arylbenzimidamides and paraformaldehyde

2-phenylquinazoline (2a, CAS: 25855-20-3)[2]

1 H NMR (400 MHz, CDCl3, ppm) δ 9.48 (s, 1H), 8.63-8.60 (m, 2H), 8.11-8.09 (m, 1H), 7.95-7.89 (m, 2H), 7.64-7.60 (m, 1H), 7.57-7.49 (m, 3H);

13C NMR (100 MHz, CDCl3, ppm) δ 161.1, 160.5, 150.8, 138.0, 134.1, 130.6, 128.6, 128.6, 128.6, 127.2, 127.1, 123.6 ;

MS (EI) ) m/z (%) 206, 197, 179, 105 (100), 77.

Wang, H. M.; Chen, H.; Chen, Y.; Deng, G. J. Org. Biomol. Chem. 2014, 12, 7792

2-phenylquinazoline

Lewis acid-catalyzed 2-arylquinazoline formation from N[prime or minute]-arylbenzimidamides and paraformaldehyde

Green Chem., 2016, Advance Article
DOI: 10.1039/C6GC02319C, Communication

Xiufang Cheng, Huamin Wang, Fuhong Xiao, Guo-Jun Deng
An efficient procedure for the synthesis of 2-arylquinazolines from N[prime or minute]-arylbenzimidamides has been developed under transition-metal-free conditions.

An efficient procedure for the synthesis of 2-arylquinazolines from N′-arylbenzimidamides has been developed under transition-metal-free conditions. In this process, stable and low-toxicity paraformaldehyde was used as the carbon source. A broad range of functional groups were well tolerated in this reaction system.

Lewis acid-catalyzed 2-arylquinazoline formation from N′-arylbenzimidamides and paraformaldehyde

Xiufang Cheng,^a Huamin Wang,^a Fuhong Xiao*^a and Guo-Jun Deng*^a

Hide Affiliations

Corresponding authors

Key Laboratory of Environmentally Friendly Chemistry and Application of Ministry of Education, College of Chemistry, Xiangtan University, Xiangtan 411105, China
E-mail: gjdeng@xtu.edu.cn, fhxiao@xtu.edu.cn
Fax: (+86)0731-5829-2251
Tel: (+86)0731-5829-8280

Green Chem., 2016, Advance Article

DOI: 10.1039/C6GC02319Chttp://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C6GC02319C?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

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Sunday, 18 September 2016

Synthesis and Antifungal Activity Against Candida Strains of Mesoionic System Derived From 1,3-Thyazolium-5-thiolate

General procedure for the preparation of ten newly synthetized compounds - 2-(p-chlorophenyl)-3-methyl-4- (p-isopropylphenyl)-1,3-thiazolium-5-(N-arylacetamide)thio chloridrates 7a-j Mesoionic 2-(p-chlorophenyl)-3-methyl-4-(pisopropylphenyl)-1,3-thiazolium-5-thiolate 5 (278 mmol) was dissolved in hot ethanol and then 2-chloro-Narylacetamides 6a-j (278 mmol) were added. The system was refluxed for 4 h and then concentrated at reduced pressure, giving a yellow-orange solid.

R1, R2 =H, H

2-(p-Chlorophenyl)-3-methyl-4-(p-isopropylphenyl)-1,3- thiazolium-5-(N-phenylacetamide)thio chloridrate 7a Yield: 92.13%;

m.p.: 130-132 °C; anal. calcd.: C, 60.58; H, 4.69; N, 5.43; S, 12.44; found: C, 60.60; H, 4.70; N, 5.42; S, 12.42;

IR (KBr) νmax / cm-1 3181 (NH), 3003 (CHAr.), 2958 (CHAlif.), 1680 (C=O), 1599, 1551, 1491 (C=C and C=N of aromatic and heterocyclic rings), 1442 (C–N of N–CH3), 1404 (C–N), 1092 (C–Cl), 1001, 922 (CHAr.), 756 (NH), 557, 537 (C–C);

1 H NMR (200 MHz, CDCl3) delta
1.30 (d, 6H, J 6.9 Hz, H-16, H-16’),
2.98 (sept, 1H, H-15), 3.79 (s, 2H, H-17),
3.84 (s, 3H, H-10), 7.09 (t, 2H, J 7.3 Hz, H-23),
7.28-7.34 (m, 4H, H-13, H-13’, H-21, H-25),
7.60 (d, 2H, J 8.1 Hz, H-8, H-8’),
7.73 (d, 2H, J 7.9 Hz, H-12, H-12’),
7.86-7.93 (t, 4H, J 7.3 Hz, H-7, H-7’, H-22, H-24),
11.02 (s, 1H, H-19);

13C NMR (50 MHz, CDCl3)
delta 170.21 (C-2), 166.81 (C-18), 152.68 (C-14),
140.28 (C-4), 138.93 (C-9), 132.04 (C-20), 131.64 (C-7, C-7’), 130.89 (C-12, C-12’),
130.27 (C-8, C-8’), 128.69 (C-22, C-24), 127.54 (C-13, C-13’),
124.09 (C-23), 123.79 (C-11), 123.59 (C-6),
120.28 (C-21, C-25), 42.24 (C-17), 40.92 (C-10), 34.21 (C-15), 23.76 (C-16, 16’).

Peixoto IN, Souza HDS, Lira BF, Silva DF, Lima EO, Barbosa-Filho JM, et al. Synthesis and Antifungal Activity AgainstCandida Strains of Mesoionic System Derived From 1,3-Thyazolium-5-thiolate. J. Braz. Chem. Soc. 2016;27(10):1807-1813

*e-mail: athayde-filho@quimica.ufpb.br
J. Braz. Chem. Soc. 2016, 27(10), 1807-1813

Synthesis and Antifungal Activity Against Candida Strains of Mesoionic System Derived From 1,3-Thyazolium-5-thiolate

Isabelle N. Peixoto; Helivaldo D. S. Souza; Bruno F. Lira; Daniele F. Silva; Edeltrudes O. Lima; José M. Barbosa-Filho; Petrônio F. de Athayde-Filho

Ten new mesoionic derivatives from the 1,3-thiazolium-5-thiolate system with substituted acetamides were synthesized, had their potential as new drug evaluated in an in silico study and in their activity as antifungal against strains of Candida albicans.