calcium‐catalyzed direct reduction of propargylic alcohols and ethers has been accomplished by using triethylsilane as a nucleophilic hydride source. At room temperature a variety of secondary propargylic alcohols was deoxygenated to the corresponding hydrocarbons in excellent yields. Furthermore, for the first time, a catalytic deoxygenation of tertiary propargylic alcohols was generallyapplicable. The
An expedient osmium(<scp>vi</scp>)/K<sub>3</sub>Fe(CN)<sub>6</sub>-mediated selective oxidation of benzylic, allylic and propargylic alcohols
作者:Rodney A. Fernandes、Venkati Bethi
DOI:10.1039/c4ra07500e
日期:——
A chemoselective osmium(VI) catalyzed oxidation of benzylic, allylic and propargylic alcohols using K3Fe(CN)6 as a secondary oxidant is described. This protocol is operationally simple and exhibits excellent chemoselectivity favouring the oxidation of benzylic alcohols over the aliphatic alcohols. A larger scale reaction was also found to be compatible.
A mild and efficient AgSbF6-catalyzed synthesis of fully substituted pyrroles through a sequential propargylation/amination/cycloisomerization reaction
fully substitutedpyrroles via a sequential propargylation/amination/cycloisomerization was accomplished using AgSbF6 as a catalyst. The one-pot three-componentreaction of propargylic alcohols, 1,3-dicarbonyl compounds, and primary amines proceeds at a mild temperature, which prevents the formation of furan by-product. The reaction was also successfully applied to the more basic aliphatic amines with
Abstract A practical synthesis of propargylic alcohols was developed by alkynylation of aldehydes mediated by zinc and allylbromide. Aromatic, aliphatic and vinyl aldehydes react with phenylacetylene or 1-hexyne to obtain various propargylic alcohols at room temperature in up to 98% yield. This method is characterized with inexpensive materials, wide substrate scope, and mild reaction conditions,
readily synthesized by electrophiliccarbocyclization of aryl propargylic alcohols in moderate to good yields under mild conditions. The resulting diiodide can be further exploited by subsequent oxidizing and coupling reactions. Both the iodine anion and cation generated from I2 are used effectively. The presence of a trace amount of water is essential for this electrophilic cyclization.