transfer (PCET). Mechanistic experiments and DFT calculations support the possibility of a concerted protonelectron-transfer (CPET) pathway. This Birch-type reduction demonstrates that a small nucleophilic organic molecule can be used as a single electron-transfer (SET) reducing agent with a proper proton source.
Continuous flow solvent free organic synthesis involving solids (reactants/products) using a screw reactor
作者:Brijesh M. Sharma、Ranjit S. Atapalkar、Amol A. Kulkarni
DOI:10.1039/c9gc02447f
日期:——
nucleophilic substitutions, protection, acylations and coupling reactions using a mechanochemical approach at a controlled temperature using a single synthesis platform. Almost minimal solvents or solvent-free conditions are used, making it a very efficient and clean synthesis of various products. A jacketed screw reactor when operated at different temperatures (0 °C to 160 °C) and over a range of
Ruthenium‐Catalyzed
<i>E</i>
‐Selective Partial Hydrogenation of Alkynes under Transfer‐Hydrogenation Conditions using Paraformaldehyde as Hydrogen Source
作者:Marcus N. A. Fetzer、Ghazal Tavakoli、Axel Klein、Martin H. G. Prechtl
DOI:10.1002/cctc.202001411
日期:2021.3.5
E‐alkenes were synthesized with up to 100 % E/Z selectivity via ruthenium‐catalyzed partial hydrogenation of different aliphatic and aromatic alkynes under transfer‐hydrogenation conditions. Paraformaldehyde as a safe, cheap and easily available solid hydrogen carrier was used for the first time as hydrogen source in the presence of water for transfer‐hydrogenation of alkynes. Optimization reactions showed
Three-Component One-Pot Synthesis of Unsymmetrical Diarylalkynes by Thermocontrolled Sequential Sonogashira Reactions Using Potassium Ethynyltrifluoroborate
作者:Taejung Kim、Kyu Hyuk Jeong、Youngseok Kim、Taesub Noh、Jaeyoung Choi、Jungyeob Ham
DOI:10.1002/ejoc.201700110
日期:2017.5.3
Sonogashira reactions with potassium ethynyltrifluoroborate and two different reactive aryl halides. The one-pot procedure was initiated by the palladium/copper-catalyzed Sonogashira coupling of potassium ethynyltrifluoroborate to an aryliodide or electron-deficient aryl bromide at 40 °C. Following a subsequent deboronative Sonogashira reaction of the in situ generated potassium (arylethynyl)trifluoroborate
a selective phosphoranation of alkynes with phosphoniumcation, which directs a concise approach to isoquinolines from unactivated alkyne and nitrile feedstocks in a single step. Mechanistic studies suggest that the annulation reaction is initiated by the unprecedented phosphoranation of alkynes, thus representing a unique reaction pattern of phosphonium salts and distinguishing it from existing protocols