An Efficient Synthesis of Symmetric and Unsymmetric Bis-(β-aminoamides) via Ugi Multicomponent Reaction
摘要:
A library of symmetrical and unsymmetrical bis-(beta-aminoamides) has been prepared starting from symmetrical secondary diamines by using a double Ugi four-component reaction. A sacrifical Mumm rearrangement, thanks to the use of 2-hydroxymethyl benzoic acid, is necessary to suppress the competing split-Ugi reaction, increasing the yield and simplifying the purification step. The scope, the reaction conditions, and the role of water in trapping the nitrilium intermediate are also discussed.
Thermal oligomerisation of aryl isocyanides: formation of pyrazino[1,2-a:4,5-a′]diindoles and indigo diarylimines
作者:Jan C. A. Boeyens、Leanne M. Cook、Yunxiang Ding、Manuel A. Fernandes、David H. Reid
DOI:10.1039/b302340k
日期:——
The aryl isocyanides 1â4 are converted at 150 °C into the hexameric pyrazino[1,2-a:4,5-aâ²]diindoles 15â19. 4-Fluorophenyl isocyanide, when heated at 135 °C, gave the hexamer 19 and the tetrameric indigo di-arylimine 9, and when kept at ambient temperature gave mainly the tetramer 9 in low yield. The structures of the hexamer 19 and the tetramer 9 were established by X-ray crystallography. Mechanisms are proposed for the oligomerisation reactions.
Multicomponent reactions (MCRs), followed by subsequent transformations, are fascinating tools for the rapid and effective synthesis of molecular scaffolds with potential pharmacological relevance. We became interested in the preparation of novel 5-aroyl-1-aryltetrazoles as (1) they still represent challenging structures not easily accessible through the methods described in literature, and (2) the α-ketotetrazolic framework may be considered as a potential bioisostere of the enonic linker of chalcones. In the present work, a novel, simple, effective and general synthesis for this class of compounds is described.
silver‐catalyzed chemoselective [4+2] annulation of aryl and heteroaryl isocyanides with α‐substituted isocyanoacetamides was developed for the facile and efficient synthesis of 2‐aminoquinolones, naphthyridines, and phenanthrolines. A mechanism for this multistep domino reaction is proposed on the basis of a 13C‐labeling experiment, according to which an unprecedented chemoselective heterodimerization
Isocyanide based multicomponent click reactions: a green and improved synthesis of 1-substituted 1<i>H</i>-1,2,3,4-tetrazoles
作者:Shrikant G. Pharande、Manuel A. Rentería-Gómez、Rocío Gámez-Montaño
DOI:10.1039/c8nj02312c
日期:——
An improved ultrasound assisted greensynthesis of 1-substituted 1H-1,2,3,4-tetrazoles via a novel isocyanide based multicomponent click reaction (IMCCR) under mild, solvent, catalyst and column-free conditions has been developed. This new, green and sustainable IMCCR methodology resulted in good to excellent yields (71–97%) in shorter reaction times.
开发了一种改进的超声辅助绿色合成方法,该方法在温和,无溶剂,无催化剂和无柱的条件下,通过基于异氰酸酯的新型多组分点击反应(IMCCR),实现了1取代的1 H -1,2,3,4-四唑的绿色合成。这种新的,绿色的,可持续的IMCCR方法可在较短的反应时间内获得良好至优异的收率(71–97%)。