Vanadium(I) Chloride and Lithium Vanadium(I) Dihydride as Selective Epimetallating Reagents for π- and σ-Bonded Organic Substrates
作者:John J. Eisch、Paul O. Fregene
DOI:10.1002/ejoc.200800461
日期:2008.9
C–O, C–N and N–N σ-bonds. Compared with the high reactivity of CrCl and LiCrH2 reagents in attacking both types of bonds, the VCl and LiVH2 reagents were much milder and selective in epimetallating π-bonds, often forming the 1:1 adduct of LiVH2 and π-bonded substrate as the major product. Finally, the vanadium reagents showed little tendency to cleave C–O, C–S and C–N bonds and a smaller scope in cleaving
Facile and Fast Pinacol Rearrangement by AlCl3 in the Solid State
作者:Parviz Rashidi-Ranjbar、Ebrahim Kianmehr
DOI:10.3390/60500442
日期:——
A facile and efficient synthetic procedure for effecting the pinacol rearrangement catalyzed by AlCl3 in the absence of solvent is developed. The rearrangement product is obtained at room temperature in a few minutes and in almost quantitative yield. Benzylic pinacols rearrange under these conditions, while aliphatic pinacols do not react.
Electroreductive cross-coupling between aldehydes and ketones or imines <i>via</i> cathodically generated dianions
作者:Lu-Jun Wang、Peng Ye、Ninghua Tan、Bo Zhang
DOI:10.1039/d2gc03177a
日期:——
class of compounds. Nonetheless, the preparation of unsymmetrical 1,2-diols via the direct cross-coupling of two different carbonylcompoundsundersimple and mild conditions remains an elusive goal. Herein, an operationally simple electroreductive cross-coupling of two common carbonyls, aldehydes and ketones using electrons as safe reducing agents is reported. By applying this new protocol, a library
Photochemical Pinacol Rearrangements of Unsymmetrical Diols
作者:Gabriela Mladenova、Gurmit Singh、Austin Acton、Lie Chen、Olga Rinco、Linda J. Johnston、Edward Lee-Ruff
DOI:10.1021/jo035439z
日期:2004.3.1
photochemical pinacol reaction of a series of nonsymmetrical 9-fluorenyl-substituted vic-diols was investigated and compared with their acid-catalyzed thermal reaction. Unlike the thermal reaction, the radiation-induced processes involve only fluorenyl cations, as is reflected in differences of product distribution between the two reactions. From the product studies, substituent migratoryaptitudes are reversed