An efficient synthesis of γ-substituted α,β-unsaturated-δ-lactams. Formal synthesis of (±)-protoemetinol
摘要:
gamma-Substituted alpha,beta-unsaturated delta-lactams I was synthesized front alpha-sulfinyl acetamides 3 in three steps. Formal synthesis of (+/-)-protoernetinol oas also reported. (C) 2002 Elsevier Science Ltd. All rights reserved.
Synthesis of Acetamide Derivatives using S-MWCNT and S-MC as an Efficient Heterogeneous Catalysts
作者:K. U Minchitha、H. N Hareesh、N Nagaraju、N Kathyayini
DOI:10.1166/jnn.2018.14563
日期:2018.1.1
carbon (S-MC) catalysts were prepared by wet impregnation method. These materials were characterized by different analytical techniques such as Powder-XRD, BET surface area analysis, SEM-EDS and TEM analysis to evaluate their bulk and surface properties. Surfaceacidity of the catalyst was measured by TPD-NH3 technique, as well as n-butyl aminetitration. The estimated surfaceacidity of S-MWCNT and
carboxylic acid and aminederivatives catalyzed by TiCp2Cl2. Arylacetic acid derivatives reacted with different amines to afford the corresponding amides in good to excellent yield except of aniline. Aryl formic acids failed to react with aniline but smoothly reacted with aliphatic amines and benzylamine in moderate to good yield, fatty acids reacting with benzyl and aliphatic amines give amides in good
Fluorination of sulfanyl amides using difluoroiodoarene reagents
作者:William B. Motherwell、Michael F. Greaney、Jeremy J. Edmunds、Jonathan W. Steed
DOI:10.1039/b209078c
日期:2002.12.19
A range of sulfur-containing amides have been fluorinated with the hypervalent iodine difluoride reagents 1, and two principal reaction pathways identified. Cephalosporin esters 2 having a heteroatom in the α-position to sulfur undergo fluorination in DCM with cleavage of the carbon–sulfur bond to form novel fluorinated β-lactams 4. Sulfides with electron-withdrawing groups in the α-position undergo α-fluorination in a process analogous to the classical Pummerer reaction. This Fluoro-Pummerer reaction has been exemplified for a range of simple α-phenylsulfanylacetamides 14–19. When β-hydrogens are present in the substrate a different route is followed, with deprotonation by basic fluoride taking place to yield vinyl sulfides 41–43. When an excess of the fluorinating reagent is used these vinyl sulfides can undergo further reaction in a novel tandem Pummerer-Additive-Pummerer process to yield α,β-difluoro sulfides 45–47.
INHIBITORS OF 15-HYDROXYPROSTAGLANDIN DEHYDROGENASE FOR STIMULATING PIGMENTATION OF THE SKIN OR SKIN APPENDAGES
申请人:MICHELET JEAN-FRANCOIS
公开号:US20110014250A1
公开(公告)日:2011-01-20
Inhibitors of 15-hydroxyprostaglandin dehydrogenase (15-PGDH), for example tetrazole, styrylpyrazole, phenylfuran, phenylthiophene, phenylpyrrazole, pyrazolecarboxamide, 2-thioacetamide and azo compounds, are useful for promoting or stimulating pigmentation of the skin and/or skin appendages and/or for preventing and/or for limiting depigmentation and/or whitening of the skin and/or skin appendages, notably for preventing and/or limiting canities.
A new methodology has been developed for the P-C bond cleavage of beta-carbonyl phosphonates. The alpha,alpha-disubstituted beta-keto phosphonates and the alpha-carbamoyl phosphonates have been shown to undergo dephosphonylation by reaction of their lithium enolate with LiAlH4, followed by quenching with aqueous H2SO4, affording regioselectively alpha,alpha-disubstituted ketone and alpha-substituted and alpha,alpha-disubstituted secondary amides.