Thiazolium-Mediated Multicomponent Reactions: A Facile Synthesis of 3-Aminofuran Derivatives

One-pot synthesis of 3-aminofurans using a simple and efficient recyclable CuI/[bmim]PF6 system

A one-pot three-component reaction of several 2-ketoaldehydes, secondary amines and terminal alkynes to access 3-aminofurans proceeded well in [bmim][PF₆] using a simple and cheap CuI catalyst. The resultant 3-aminofuran products were easily isolated using diethyl ether and the CuI/[bmim][PF₆] system was reused six times with a slight decrease in the activity.

New frontiers in the transition-metal-free synthesis of heterocycles from alkynoates: an overview and current status

This review highlights the successful utilization of transition-metal-free approaches for the modular assembly of various heterocycles from alkynoates.

Towards the Shell Biorefinery: Sustainable Synthesis of the Anticancer Alkaloid Proximicin A from Chitin

A shell biorefinery would involve fractionation of crustacean shells and incorporation of the components into value-added products, particularly those that contain nitrogen. In a proof-of-concept study that validates this concept, the anticancer alkaloid proximicin A has been synthesized from the chitin-derived platform chemical 3-acetamido-5-acetylfuran (3A5AF). This study accentuates the leading role chitin is likely to play in the sustainable production of nitrogen-containing fine chemicals that are not directly attainable from lignocellulose.

An uncommon multicomponent reaction involving nucleophilic heterocyclic carbenes: facile synthesis of fully substituted cyclopentanones

An unprecedented three component reaction involving arylidene oxazolone, enal and NHC, leading to the synthesis of fully substituted cyclopentanone derivatives with three contiguous stereocenters, is reported.

Thiazolium salt-catalyzed [3 + 2 + 1] cyclization for the synthesis of trisubstituted 2-pyrones using arylglyoxals as a carbonyl source

A new thiazolium salt-catalyzed [3 + 2 + 1] cyclization of acetylenedicarboxylates with arylglyoxals has been developed, enabling organocatalytic umpolung to access trisubstituted 2-pyrones with good yields via C–C bond cleavage.

Recent advances in N-heterocyclic carbene catalyzed achiral synthesis

N-Heterocyclic carbenes (NHCs) have emerged as powerful and elegant organocatalysts in a variety of newly developed and unprecedented enantioselective transformations due to their unique umpolung capacity. As a supplement to conventional enantioselective organocatalysis, NHC-induced non-asymmetric catalysis has gradually attracted much interest in recent years. Herein, this review aims to reveal the recent developments in NHC-promoted non-asymmetric umpolung transformations resulting in the expeditious construction of versatile achiral natural heterocycles, carbocycles and acylated products.

Cascade bicyclizations of o-alkynyl aldehydes with thiazolium salts: a new access toward poly-functionalized indeno[2,1-b]pyrroles

A new cascade bicyclization of o-alkynyl aldehydes with thiazolium salts is described, in which 25 examples of densely functionalized indeno[2,1-b]pyrroles are achieved in a functional-group-compatible manner. Thiazole carbenes generated in situ from thiazolium salts play dual roles as reaction partners and as NHC catalysts. The synthetic utility of these bicyclization reactions results in subsequent C-C bond-forming events to rapidly build up molecular complexity.

Facile synthesis of substituted 3-aminofurans through a tandem reaction of N-sulfonyl-1,2,3-triazoles with propargyl alcohols

A relay catalysis strategy for substituted 3-aminofurans synthesis has been developed.

A theoretical investigation of substituent effects on the stability and reactivity of N-heterocyclic olefin carboxylates

Introduction of four phenyl groups at C-position and N-position not only favors decarboxylation but also ensures NHO as a strong nucleophile.

Mechanism of N-heterocyclic carbene-catalyzed chemical fixation of CO2 with aziridines: a theoretical study

Free NHC is a catalyst precursor, while the carboxylate intermediate is the active species in the catalytic cycle.