Huisgen [3+2] dipolar cycloaddition of 6″-azido-6″-deoxy-α-galactosyl ceramide 11 with a range of alkynes (or a benzyne precursor) yielded a series of triazole-containing α-galactosyl ceramide (α-GalCer) analogues in high yield. These α-GalCer analogues and the precursor azide 11 were tested for their ability to activate iNKT cells and stimulate IL-2 cytokine secretion in vitro, and IFN-γ and I...

1,3-Dipolar cycloaddition of pyridynes and organic azides was investigated. Thus, 3,4-pyridynes and 2,3-pyridynes were reacted with various organic azides under mild conditions to afford the corresponding [1,2,3]triazolo[4,5-c]pyridines and [1,2,3]triazolo[4,5-b]pyridines, respectively. In the case of the reaction of 3,4-pyridyne, it was also found that a substituent on pyridine ring affected t...

1,3-dipolar Cycloaddition (DC) reactions have emerged as one of the important type of cycloaddition reactions from the view point of chemical and biological industry. Particularly the Azide-Alkyne Cycloaddition, also known as “Click Chemistry” has opened up new challenges in front of medicinal and pharmaceutical chemists. Bioconjugation is a technique of coupling two different biomolecules by c...

The [4+2] cycloaddition reaction is an enabling transformation in modern synthetic organic chemistry, but there are only limited examples of dedicated natural enzymes that can catalyze this transformation. Thiopeptides (or more formally thiazolyl peptides) are a class of thiazole-containing, highly modified, macrocyclic secondary metabolites made from ribosomally synthesized precursor peptides....

Abstract A concise total synthesis of (+)-aphanorphine is described. The key features the strategy include a Pd-catalyzed intermolecular trimethylenemethane [3+2]-cycloaddition to form ring C and Co-catalyzed radical cyclization through hydrogen-atom transfer close B. was completed in six steps.

We report an assay for determining the number of fluorophores conjugated to single plasmid DNA molecules and apply this to compare the efficiency of fluorophore coupling strategies for covalent DNA labelling. We compare a copper-catalyzed azide-alkyne cycloaddition reaction, amine to N-hydroxysuccinimidyl ester coupling reaction and strain-promoted azide-alkyne cycloaddition reaction for fluore...

The death of professor Rolf Huisgen (1920-2020) was announced on March 26th 2020, in the midst COVID-19 pandemic. Professor emeritus at University Munich Germany, and studied detail mechanism 1,3-dipolar cycloaddition reaction, significantly expanding its scope. Even though he did not discover this it through his studies that became important organic synthesis. Indeed, honor work, reaction know...

Natural and abundant plant triterpenoids are attractive starting materials for the synthesis of conformationally rigid chiral building blocks functional soft materials. Here, we report rational design three oleanolic acid–triazole–spermine conjugates, containing either one or two spermine units in target molecules, using Cu(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction. The resulting ...

The enzyme-directed synthesis is an emerging fragment-based lead discovery approach in which the biological target is able to assemble its own multidentate ligands from a pool of building blocks. Here, we report for the first time the use of the human acetylcholinesterase (AChE) as an enzyme for the design and synthesis of new potent heterodimeric huprine-based inhibitors. Both the specific cli...

A new method for the rapid and efficient coupling of homopolymers to yield di- and triblock copolymers as well as cyclic polymers using the 3 + 2 π Huisgen copper catalyzed cyclo-addition reaction has been developed. This facile method utilizes commercially available Cu nanoparticles that are tolerant to O(2), easily removable and recyclable.