The title compound, C(33)H(49)NO(3), is the propargyl-amide of 18β-glycyrrhetinic acid, a penta-cyclic triterpenoid of inter-est as a therapeutic agent. The five six-membered rings of the glycyrrhetinic acid moiety show normal geometries, with four rings in chair conformations and the unsaturated ring C in a half-chair conformation. In the crystal, the terminal N-propargylcarboxamide group has ...

Here, we report on a new temperature responsive polymer brush system with a terminal ‘‘click’’ functionality. Bifunctionalized poly(N-isopropylacrylamide) (PNiPAAm) with distinct functional end groups was synthesized by atom transfer radical polymerization (ATRP) and grafted to a modified silicon substrate. The presence of the active terminal alkyne functionality is validated using an azidemodi...

Strain-promoted alkyne-nitrone cycloadditon (SPANC) was optimized as a versatile strategy for dual functionalization of peptides and proteins. The usefulness of the dual labeling protocol is first exemplified by the simultaneous introduction of a chloroquine and a stearyl moiety, two endosomal escape-improving functional groups, into the cell-penetrating peptide hLF (human lactoferrin). Additio...

A racemic Au(I)-catalyzed three-component reaction has been developed to prepare cyclic carbamimidates from imines, terminal alkynes, and sulfonylisocyanates. This reaction exploits the carbophilic π-acidity of gold catalysts to first activate an alkyne toward deprotonation and secondly, to activate the internal alkyne generated toward intramolecular O-cyclization. Unlike similar previously rep...

Substituted 2, 4- diphenyl quinolines were synthesized by a multicomponent domino reaction of anilines, aldehydes and terminal aryl alkynes. The synthetic pathway involves the formation of an imine, followed by the intermolecular addition of an alkyne to the imine. This intermediate immediately undergoes ring closure and oxidative aromatization. The reaction is catalyzed by natural kaolin, a st...

A silver-catalyzed intermolecular aminosulfonylation of terminal alkynes with sodium sulfinates and TMSN3 is reported. This three-component reaction proceeds through sequential hydroazidation of the terminal alkyne and addition of a sulfonyl radical to the resultant vinyl azide. The method enables the stereoselective synthesis of a wide range of β-sulfonyl enamines without electron-withdrawing ...

substituted 2, 4- diphenyl quinolines were synthesized by a multicomponent domino reaction of anilines, aldehydes and terminal aryl alkynes. the synthetic pathway involves the formation of an imine, followed by the intermolecular addition of an alkyne to the imine. this intermediate immediately undergoes ring closure and oxidative aromatization. the reaction is catalyzed by natural kaolin, a st...

Owing of their accessibility and wide range reactivities, alkynes make for fascinating building blocks. Either a selective alkyne carbon-carbon triple bond reaction or activation the terminal C-H may be employed to functionalize them. Monocationic coinage metal complexes with d10 electronic configuration are effective catalysts activation. Silver(I) gold(I) N-heterocyclic (NHC) systems emerging...

SnCl4·5H2O is a highly efficient catalyst in the hydration of terminal alkynes that affords carbonyl compounds in high to good yields. Under the optimized reaction conditions, the moderate to excellent yields of corresponding ketones were obtained when the aromatic and aliphatic terminal alkynes were used as substrates. With using diphenylacetylene as an internal alkyne, the corresponding keton...