Dicobalt Hexacarbonyl Complexes of Alkynyl Imines in a Sequential Staudinger/Pauson−Khand Process. A Route to New Fused Tricyclic β-Lactams
摘要:
Dicobalt hexacarbonyl complexes of alkynyl imines were allowed to react with ketenes via Staudinger reaction. Sequential [2 + 2] cycloaddition/Pauson-Khand reaction led to structurally new fused-tricyclic beta-lactams and fused-azabicyclic cyclopentenones. Chemoselectivity, scope, and limitation of the process were investidated.
DIANION OF 2-(METHYLTHIO)-4-PENTENOIC ACID: A USEFUL REAGENT FOR THE PREPARATION OF 5-METHYLENE-2(5<i>H</i>)-FURANONES
作者:Kazuhiko Tanaka、Makoto Terauchi、Aritsune Kaji
DOI:10.1246/cl.1982.351
日期:1982.3.5
A general and mild approach to 5-methylene-2(5H)-furanones has been demonstrated, which involves (a) the alkylation of dianion of 2-(methylthio)-4-pentenoic acid, (b) the cyclization followed by dehydrosulfenylation, and (c) the facile dehydroiodination by Na2CO3.
7-Amino 2-lower alkyl-2 or 3-cephem-4-carboxylic acid derivatives and
申请人:Fujisawa Pharmaceutical Co., Ltd.
公开号:US04113940A1
公开(公告)日:1978-09-12
A compound of the formula ##STR1## wherein R.sup.1 is amino or substituted amino, R.sup.2 is carboxy or protected carboxy, R.sup.3 is lower alkyl and X is --S-- or ##STR2## or a pharmaceutically acceptable salt thereof is effective against various microorganisms.
Tandem Organocatalytic Cycloaromatization/Intramolecular Friedel–Crafts Alkylation Sequence for the Synthesis of Indolizinones and Pyrrolo-azepinone Derivatives
作者:Fernando Rabasa-Alcañiz、María Sánchez-Roselló、Santos Fustero、Carlos del Pozo
DOI:10.1021/acs.joc.9b01314
日期:2019.9.6
The organocatalytic synthesis of indolizinones and pyrrolo-azepinones has been accomplished in a tandem fashion through a sequence that comprises initial cycloaromatization followed by intramolecular Friedel–Crafts alkylation. The process takes place under Brønsted acid catalysis, giving rise to final products in moderate to good yields. Attempts to carry out the tandem protocol in an enantioselective
Ligands containing elements of group VIB. Part V. Thermodynamics of silver complex formation of some saturated and unsaturated (alkyl-thio)acetic and (alkylseleno)acetic acids
作者:D. S. Barnes、G. J. Ford、L. D. Pettit、C. Sherrington
DOI:10.1039/j19710002883
日期:——
Thermodynamic constants for the formation of silvercomplexes of some saturated and unsaturated (alkylthio) and (alkylseleno)acetic acids have been calculated by measuring formation constants over the range 0–40° at /= 0·20M. In particular, co-ordination to silver through an olefinic double bond has been shown to have a large favourable enthalpy change, strongly opposed by entropy changes. An analysis