Es werden Umsetzungenvon Dithiocarbamaten mit weiteren β‐Lactonen zu 2 und deren Cyclisierung zu den 4‐Oxo‐2‐thioxo‐tetrahydro‐1,3‐thiazinen 3 beschrieben. Mit Diketenderivaten (β‐Propiolactonen mit exocyclischer Doppelbindung) werden keine 1,3‐Thiazine 6 erhalten, sondern unter Schwefelkohlenstoff‐Eliminierung β‐Ketosäureamide 7.
Malonicanhydrides decompose at or below room temperature, to form a ketene and carbon dioxide. Rate constants for the thermal decomposition of malonic, methylmalonic, and dimethylmalonic anhydrides were measured by NMR spectroscopy at various temperatures, and activation parameters were evaluated from the temperature dependence of the rate constants. Methylmalonic anhydride is the fastest, with the
Mechanistic studies of the phosphine-catalyzed homodimerization of ketoketenes
作者:Pei-Hsun Wei、Ahmad A. Ibrahim、Mukulesh Mondal、Divya Nalla、Gero D. Harzmann、Frank A. Tedeschi、Kraig A. Wheeler、Nessan J. Kerrigan
DOI:10.1016/j.tetlet.2010.10.026
日期:2010.12
ketoketenes has been explored and compared with that of the previously reported trialkylphosphite-mediated reactions. NMR studies of the PBu3-catalyzed reaction implicated the involvement of tetravalent phosphonium intermediates. Phosphonium intermediates in the catalytic cycle were trapped through reaction with trimethylsilyl chloride and 4-chlorobenzaldehyde, and the resulting products were characterized
Josiphos-Catalyzed Asymmetric Homodimerization of Ketoketenes
作者:Ahmad A. Ibrahim、Pei-Hsun Wei、Gero D. Harzmann、Nessan J. Kerrigan
DOI:10.1021/jo101867m
日期:2010.11.19
phosphine-catalyzed homodimerization of ketoketenes that provides access to a variety of highlysubstitutedketoketenedimerβ-lactones (11 examples) is reported. The Josiphos catalytic system displays good to excellent enantioselectivity (up to 96% ee). Ring-opening reactions of the enantioenriched ketoketenedimers were also carried out to access 1,3-diketones, enolesters, and β-hydroxyketones with good
METHOD OF PRODUCING A METAL PHTHALOCYANINE COMPOUND, AND METHOD OF PRODUCING A PHTHALOCYANINE COMPOUND AND AN ANALOGUE THEREOF
申请人:Tateishi Keiichi
公开号:US20090247742A1
公开(公告)日:2009-10-01
A method of producing a metal phthalocyanine compound, which contains: conducting a reaction between at least two compounds selected from among Compounds A to F of formula (I), and a metal compound, in a buffer solution of an organic base or an inorganic base and an acid, in the presence of a dehydrating agent:
wherein R is a hydrogen atom or a substituent; l is an integer of 0 to 4; a plurality of Rs may be the same or different from each other when l is 2 to 4; and G is a group of atoms necessary for forming at least one of a 5- or 6-membered aromatic ring and a 5- or 6-membered hetero ring.