Sunday 17 September 2017

Ex Situ Generation of Sulfuryl Fluoride for the Synthesis of Aryl Fluorosulfates

Abstract Image
A convenient transformation of phenols into the corresponding aryl fluorosulfates is presented: the first protocol to completely circumvent direct handling of gaseous sulfuryl fluoride (SO2F2). The proposed method employs 1,1′-sulfonyldiimidazole as a precursor to generate near-stoichiometric amounts of SO2F2 gas using a two-chamber reactor. With NMR studies, it was shown that this ex situ gas evolution is extremely rapid, and a variety of phenols and hydroxylated heteroarenes were fluorosulfated in good to excellent yields.

Ex Situ Generation of Sulfuryl Fluoride for the Synthesis of Aryl Fluorosulfates

Molecular Design and Synthesis, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, Box 2404, 3001 Leuven, Belgium
Org. Lett., Article ASAP
DOI: 10.1021/acs.orglett.7b02522

http://pubs.acs.org/doi/abs/10.1021/acs.orglett.7b02522?utm_content=bufferd3ad9&utm_medium=social&utm_source=twitter.com&utm_campaign=buffer

4-fluoro-[1,1'-biphenyl]-4-yl sulfurofluoridate (compound 1) 
General procedure A was followed using 192 mg of 4-fluoro-4’-hydroxybiphenyl (98 wt%, 1.0 mmol, 1.0 eq.). The crude reaction mixture was purified by solid-phase flash column chromatography on silicagel (heptane, 100%). The title compound was obtained as a white solid (258 mg, 96%). Rf = 0.39 (heptane/ethyl acetate, 9/1). Melting point = 47 – 49 °C.
1 H NMR (400 MHz, CDCl3): 7.62 (d, J = 8.5 Hz, 1H), 7.52 (dd, J = 8.1, 5.5 Hz, 1H), 7.41 (d, J = 8.5 Hz, 1H), 7.16 (t, J = 8.5 Hz, 1H). 
13C NMR (101 MHz, CDCl3): δ 163.05 (d, J = 247.9 Hz), 149.51, 141.17, 135.55 (d, J = 3.3 Hz), 129.06, 128.98, 121.42, 116.13 (d, J = 21.6 Hz).
19F NMR (376 MHz, CDCl3): δ 37.18, -114.68 (m).
 IR (neat) cm-1 : 1437, 1232, 921, 815. 
CHN: calculated for C12H8F2O3S: C 53.33%, H 2.98%, N 0.00%; found: C 53.43%, H 3.26%, N 0.00%.



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2,5-Bis(morpholinomethyl)furan


2,5-Bis(morpholinomethyl)furan, 11

Yield 98%, 1H NMR (CDCl3) = 6.13 (s, 2H), 3.70 (m, 8H), 3.51 (s, 4H), 2.45 (m, 8H);

13C NMR (CDCl3) = 150.9, 109.7, 66.8, 55.3, 53.2 ppm.

 m/z HRMS (ESI) Calcd. for C14H22N2O3 [M+H]: 267.1703. Found 267.1703.






Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC02211E, Paper
F. A. Kucherov, K. I. Galkin, E. G. Gordeev, V. P. Ananikov
Efficient one-pot synthesis of tricyclic compounds from biobased 5-hydroxymethylfurfural (HMF) is described using a [4 + 2] cycloaddition reaction.

Efficient route for the construction of polycyclic systems from bioderived HMF

 Author affiliations
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Wednesday 19 July 2017

Iron-catalyzed dehydrogenation reactions and their applications in sustainable energy and catalysis



Iron-catalyzed dehydrogenation reactions and their applications in sustainable energy and catalysis
Catal. Sci. Technol., 2017, Advance Article
DOI: 10.1039/C7CY00879A, Minireview
Ekambaram Balaraman, Avanashiappan Nandakumar, Garima Jaiswal, Manoj K. Sahoo
This review article describes recent developments of iron-based acceptorless dehydrogenation (AD) reactions of fundamentally important feedstock, as a route to sustainable chemical synthesis and energy storage applications

Catalysis Science & Technology

Iron-catalyzed dehydrogenation reactions and their applications in sustainable energy and catalysis

 

Abstract

Inspired by nature, chemists have designed new catalysts in the pursuit of selective bond activation and chemical transformations. Emergent biological systems often use earth-abundant first-row transition elements as catalytically active sites to facilitate specific and highly selective chemical processes. The design of a new catalytic system based on abundant and inexpensive catalysts, particularly the iron-based catalysts, for fundamentally significant synthetic transformations under environmentally benign conditions is an important paradigm in chemical synthesis. In recent times, iron-based catalytic systems have shown unprecedented reactivity in the acceptorless dehydrogenation reactions of feedstock chemicals, with the liberation of molecular hydrogen as the by-product, and have enabled greener chemical synthetic methods and alternative energy storage systems. Indeed, it has been demonstrated that the proper design of iron catalysts by judiciously choosing ligands, can aid in the development of new sustainable energy storage systems and catalysis. This tutorial review focuses on the recent development of iron-based dehydrogenation reactions of fundamentally important feedstock, as a route to sustainable chemical synthesis and energy storage applications. The emerging area of the iron-based dehydrogenation strategy provides an opportunity to make industrially applicable, cost-effective and environmentally benign catalytic systems

eb.raman@
Dr.Ekambaram Balaraman
Catalysis Division
CSIR-National Chemical Laboratory
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Saturday 3 June 2017

Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air




Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC00977A, Communication
Song Yao, Kaijing Zhou, Jiabing Wang, Hongen Cao, Lei Yu, Jianzhang Wu, Peihong Qiu, Qing Xu
An atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated aerobic oxidative reaction of 2-aminoarylmethanols and nitriles in air.


http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC00977A?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air

 Author affiliations

Abstract

By using air as the superior oxidant, a highly atom-efficient synthesis of 2-substituted quinazolines is developed by a CsOH-mediated direct aerobic oxidative reaction of the readily available and stable 2-aminoarylmethanols and nitriles. Effectively working as the promoter in the alcohol oxidation, nitrile hydration, and cyclocondensation steps, CsOH is the best base for the reaction. A similar method can also be extended to the synthesis of substituted quinolines starting from methyl ketones instead of nitriles.
Graphical abstract: Synthesis of 2-substituted quinazolines by CsOH-mediated direct aerobic oxidative cyclocondensation of 2-aminoarylmethanols with nitriles in air










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