Totalsynthesis of the title compounds is described. The key intermediate, dehydro-pentacyclic 13, is prepared in a sequence involving Pictet-Spengler reaction and DDQ oxidation. The key step in the synthesis was the dihydroxylation of 13 to afford the cis-diol 54, which was performed by direct oxidation with osmium tetroxide, whereas treatment of 13 with N-bromo-succinimide provided the trans-diol
Fluoroboric acid adsorbed on silica-gel (HBF4–SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds
作者:Gaurav Sharma、Raj Kumar、Asit K. Chakraborti
DOI:10.1016/j.tetlet.2008.04.144
日期:2008.6
found to be a new and highly efficient heterogeneouscatalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds under solvent-free conditions. In the case of 1,3-diaryl-2-propenones, the reactions are best carried out in MeOH. The rate of thia-Michael addition was dependent on the steric hindrance at the β-carbon of the α,β-unsaturated carbonyl substrate as well as surrounding the thiol
Desulfurative Chlorination of Alkyl Phenyl Sulfides
作者:Daniele Canestrari、Stefano Lancianesi、Eider Badiola、Chiara Strinna、Hasim Ibrahim、Mauro F. A. Adamo
DOI:10.1021/acs.orglett.7b00077
日期:2017.2.17
The chlorination of readily available secondary and tertiary alkyl phenyl sulfides using (dichloroiodo)benzene (PhICl2) is reported. This mild and rapid nucleophilic chlorination is extended to sulfa-Michael derived sulfides, affording elimination-sensitive β-chloro carbonyl and nitro compounds in good yields. The chlorination of enantioenriched benzylic sulfides to the corresponding inverted chlorides
<sup>13</sup>C Nuclear Magnetic Resonance Spectra of Organic Sulfur Compounds: Cyclic Sulfides, Sulfoxides, Sulfones, and Thiones
作者:M. S. Chauhan、I. W. J. Still
DOI:10.1139/v75-408
日期:1975.10.1
data have been obtained for more than 50 thiochromanone and related sulfoxide and sulfone derivatives. The assignments of the various resonances in the most important of these have been made using the limited data already available and also by comparison with certain model compounds, such as thioanisole, diphenyl sulfide, and the corresponding sulfoxides and sulfones.Within each of these three series
Iodine catalyzed conjugate addition of mercaptans to α,β-unsaturated carboxylic acids under solvent-free condition
作者:Shijay Gao、Tingkai Tzeng、M.N.V. Sastry、Cheng-Ming Chu、Ju-Tsung Liu、Chunchi Lin、Ching-Fa Yao
DOI:10.1016/j.tetlet.2006.01.080
日期:2006.3
We have described herein molecular iodine catalyzed Michael addition of thiol to α,β-unsaturated carboxylic acids. This environmentally benign catalytic system (iodine) used under mild and solvent-free conditions to achieve the corresponding adducts in excellent yield.