Hydroxyapatite-Supported Palladium-Catalyzed Efficient Synthesis of (E)-2-Alkene-4-ynecarboxylic Esters. Intense Fluorescene Emission of Selected Compounds

The Journey of 1-Keto-1,2,3,4-Tetrahydrocarbazole Based Fluorophores: From Inception to Implementation

Carbazole is a unique template associated with several biological activities. It is due to the diverse and versatile biological properties of carbazole derivatives that they are of immense interest to the research community. 1-keto-1,2,3,4-tetrahydrocarbazoles are important synthetic intermediates to obtain carbazole derivatives. Several members of this family emit fluorescence on photoexcitation. In the context of biochemical and biophysical research, designing and characterising small molecule environment sensitive fluorophores is extremely significant. This article aims to be a state of the art review with synthetic and photophysical details of a variety of fluorophores based on 1-keto-1,2,3,4-tetrahydrocarbazole skeleton.

Synthesis of 2-acetal-1,3-enynes by Sonogashira reaction of bromovinyl acetals with alkynes: application to the formal synthesis of a glucagon antagonist

The preparation of functionalized 1,3-enynes bearing an acetal moiety at the 2-position has been studied through Sonogashira reaction of bromovinyl acetals with various alkyl- and aryl-substituted terminal alkynes.

Synthesis of alkynes from non-alkyne sources

This review contains a compilation of the literature for the synthesis of alkynes from non-alkyne sources.

Cobalt-Catalyzed E-Selective Cross-Dimerization of Terminal Alkynes: A Mechanism Involving Cobalt(0/II) Redox Cycles

A highly E-selective cross-dimerization of terminal alkynes with either terminal silylacetylenes, tert-butylacetylene, or 1-trimethylsilyloxy-1,1-diphenyl-2-propyne in the presence of a dichlorocobalt(II) complex bearing a sterically demanding 2,9-bis(2,4,6-triisopropylphenyl)-1,10-phenanthroline, activated with two equivalents of EtMgBr, gives a variety of (E)-1,3-enynes. A well-characterized diolefin/cobalt(0) complex, with divinyltetramethyldisiloxane, acted as a catalytically active species without any activation, clearly indicating that a cobalt(0) species is involved in the catalytic cycle.

(E)-Di-iodination of Alkynes Using Dried Dowex H+/NaI Approach

We investigated the usefulness of the dried Dowex H⁺/NaI approach for the selective di-iodination of alkynes. The Dowex H⁺/NaI approach selectively produces only (E)-di-iodinated products; it is very straightforward and nontoxic. The utilization of 2-propanol as a solvent in the reactions can be considered as a "green" approach and the method maybe extended to radio-iodination. The method allows access to highly important building blocks. An initial example of the di-iodination and esterification in the same one-pot reaction is also presented.

Rhodium-catalyzed chemo- and regioselective cross-dimerization of two terminal alkynes

Cross-dimerization of terminal arylacetylenes and terminal propargylic alcohols/amides has been achieved in the presence of a rhodium catalyst. This method features high chemo- and regioselectivities rendering convenient and atom economical access to functionalized enynes.