A Reliable Method to Create Adjacent Acid-Base Pair Sites on Silica through Hydrolysis of Pre-anchored Amide
作者:Wontae Kim、Loida O. Casalme、Taiki Umezawa、Fuyuhiko Matsuda、Ryoichi Otomo、Yuichi Kamiya
DOI:10.1246/cl.190773
日期:2020.1.5
A method to create adjacent acid-base pair sites, which are carboxyl and amino groups, respectively, on silica through hydrolysis of pre-anchored amide is proposed. This method can produce an adjacent acid-base pair site. The catalyst showed excellent catalytic performance for aldol condensation of 4-nitrobenzaldehyde with acetone, overwhelming the catalyst having only amino group and an acid-base catalyst prepared in a conventional manner.
Preparations on N-(phenylthio)amides from secondary amides are described, and these species are shown to be efficient precursors for amidyl radicals in Bu3SnH mediated reactions; cyclizations of δ,ε-unsaturated amidyl radicals from these precursors and their use in measurement of relative rate constants are reported.
A convenient approach to acyclic unsaturated amino acids via ring-closing metathesis
作者:Hani Mutlak A. Hassan、Fraser K. Brown
DOI:10.1039/c003138k
日期:——
An efficient synthetic methodology to gain access to novel cis- and trans-unsaturated amino acids via ring-closing metathesis in high yields is described.
描述了一种高效的合成方法,通过闭环复分解反应以高产率获得新型的顺式和反式不饱和氨基酸。
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
[reaction: see text] The readily available N-(O-ethyl thiocarbonylsulfanyl)amides are powerful amidyl radical precursors that undergo 5-exo cyclization to give pyrrolidinone derivatives via a radical-chain reaction initiated by a small amount of lauroyl peroxide.