BODIPY dyes and their derivatives: syntheses and spectroscopic properties.

Although fire is now rarely used in synthetic chemistry, it was not until Robert Bunsen invented the burner in 1855 that the energy from this heat source could be applied to a reaction vessel in a focused manner. The Bunsen burner was later superseded by the isomantle, oil bath, or hot plate as a source for applying heat to a chemical reaction. In the past few years, heating and driving chemical reactions by microwave energy has been an increasingly popular theme in the scientific community. This nonclassical heating technique is slowly moving from a laboratory curiosity to an established technique that is heavily used in both academia and industry. The efficiency of "microwave flash heating" in dramatically reducing reaction times (from days and hours to minutes and seconds) is just one of the many advantages. This Review highlights recent applications of controlled microwave heating in modern organic synthesis, and discusses some of the underlying phenomena and issues involved.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/anie.200400655

Controlled microwave heating in modern organic synthesis.

4.2.8. Reductive Coupling 3109 5. Reaction of Aromatic Compounds 3110 5.1. Electrophilic Substitutions 3110 5.2. Radical Substitution 3111 5.3. Oxidative Coupling 3111 5.4. Photochemical Reactions 3111 6. Reaction of Carbonyl Compounds 3111 6.1. Nucleophilic Additions 3111 6.1.1. Allylation 3111 6.1.2. Propargylation 3120 6.1.3. Benzylation 3121 6.1.4. Arylation/Vinylation 3121 6.1.5. Alkynylation 3121 6.1.6. Alkylation 3121 6.1.7. Reformatsky-Type Reaction 3122 6.1.8. Direct Aldol Reaction 3122 6.1.9. Mukaiyama Aldol Reaction 3124 6.1.10. Hydrogen Cyanide Addition 3125 6.2. Pinacol Coupling 3126 6.3. Wittig Reactions 3126 7. Reaction of R,â-Unsaturated Carbonyl Compounds 3127

Organic Reactions in Aqueous Media with a Focus on Carbon−Carbon Bond Formations: A Decade Update

Introduction
PaDEL-Descriptor is a software for calculating molecular descriptors and fingerprints. The software currently calculates 797 descriptors (663 1D, 2D descriptors, and 134 3D descriptors) and 10 types of fingerprints. These descriptors and fingerprints are calculated mainly using The Chemistry Development Kit. Some additional descriptors and fingerprints were added, which include atom type electrotopological state descriptors, McGowan volume, molecular linear free energy relation descriptors, ring counts, count of chemical substructures identified by Laggner, and binary fingerprints and count of chemical substructures identified by Klekota and Roth.

Methods
PaDEL-Descriptor was developed using the Java language and consists of a library component and an interface component. The library component allows it to be easily integrated into quantitative structure activity relationship software to provide the descriptor calculation feature while the interface component allows it to be used as a standalone software. The software uses a Master/Worker pattern to take advantage of the multiple CPU cores that are present in most modern computers to speed up calculations of molecular descriptors.

Results
The software has several advantages over existing standalone molecular descriptor calculation software. It is free and open source, has both graphical user interface and command line interfaces, can work on all major platforms (Windows, Linux, MacOS), supports more than 90 different molecular file formats, and is multithreaded.

Conclusion
PaDEL-Descriptor is a useful addition to the currently available molecular descriptor calculation software. The software can be downloaded at http://padel.nus.edu.sg/software/padeldescriptor. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2011

https://onlinelibrary.wiley.com/doi/pdf/10.1002/jcc.21707

PaDEL‐descriptor: An open source software to calculate molecular descriptors and fingerprints

Hydrothermal technologies are broadly defined as chemical and physical transformations in high-temperature (200–600 °C), high-pressure (5–40 MPa) liquid or supercritical water. This thermochemical means of reforming biomass may have energetic advantages, since, when water is heated at high pressures a phase change to steam is avoided which avoids large enthalpic energy penalties. Biological chemicals undergo a range of reactions, including dehydration and decarboxylation reactions, which are influenced by the temperature, pressure, concentration, and presence of homogeneous or heterogeneous catalysts. Several biomass hydrothermal conversion processes are in development or demonstration. Liquefaction processes are generally lower temperature (200–400 °C) reactions which produce liquid products, often called “bio-oil” or “bio-crude”. Gasification processes generally take place at higher temperatures (400–700 °C) and can produce methane or hydrogen gases in high yields.

/pdf/thermochemical-biofuel-production-in-hydrothermal-media-a-57itjyvhnt.pdf

Thermochemical biofuel production in hydrothermal media: A review of sub- and supercritical water technologies

Adducts (8,12), derived from benzotriazole (7), glyoxylic ester (6) or acid (11), and an amide (5), react with ammonia in a novel, convenient route to monoacylated α-aminoglycines (9,13) useful for the synthesis of peptide analogues.

Benzotriazole-Assisted Synthesis of Monoacyl-α-aminoglycines.

4-Aryl(or heteroaryl)-5-heterosubstituted 1,2,3-thiadiazoles on heating in the presence of sodium hydride undergo ring opening with nitrogen elimination followed by recyclization to form the corresponding 1,4-benzoxathiins and 1,4-benzodithiins.

Benzo‐1,4‐oxathiins and Benzo‐1,4‐dithiins from 4,5‐Disubstituted 1,2,3‐Thiadiazoles.

A new general route to conjugated enynyl ketones was developed based on a two-step procedure. First, palladium-catalyzed cross-coupling reactions of 1-(benzotriazol-1-yl)propargyl ethyl ether (3) and vinyl triflates or vinyl bromides afforded the key intermediates [1-(benzotriazol-1-yl)-1-enynyl]methyl ethyl ethers 5a-d in good yields. Then reactions of compounds 5 with primary halides gave intermediates 8, which were hydrolyzed by dilute acid to enynyl ketones 9a-g. Similar palladium-catalyzed coupling reactions of 3 with various aryl iodides followed by an analogous sequence afforded aryl-substituted propargyl ethers 12a-d and thence alkynyl ketones 13a,b.

Palladium‐Catalyzed Cross‐Coupling Syntheses of Benzotriazolyl Enynes and a General Route to Enynyl Ketones and Alkynyl Ketones.

Silyl enol ethers react with 1-chlorobenzotriazole to provide a new general method for the preparation of α-benzotriazolyl-substituted ketones.

Novel Synthesis of α‐Benzotriazolyl‐Substituted Ketones.

The reaction of lithiated (benzothiazol-2-ylthio) (benzotriazol-1-yl)-methane with n-propyl iodide yielded: (benzothiazol-2-yl) (benzothiazol-2-yl-thio) (benzotriazol-1-yl)methane, (benzothiazol-2-yl) (benzotriazol-1-yl) (propylthio)methane and (benzotriazol-1-yl) (propylthio)methane. Reactions of 2-methylthiobenzothiazole with 1-methylbenzotriazole 2-methylbenzotriazole and (benzotriazol-1-yl) (phenylthio)methane are also described

Alan R. Katritzky

Papers

Benzotriazole-Assisted Synthesis of Monoacyl-α-aminoglycines.

Benzo‐1,4‐oxathiins and Benzo‐1,4‐dithiins from 4,5‐Disubstituted 1,2,3‐Thiadiazoles.

Palladium‐Catalyzed Cross‐Coupling Syntheses of Benzotriazolyl Enynes and a General Route to Enynyl Ketones and Alkynyl Ketones.

Novel Synthesis of α‐Benzotriazolyl‐Substituted Ketones.

The Diverse Reactivity of (Benzothiazol-2-ylthio)-(benzotriazol-1-yl) methane.