Related Experiment Video
Updated: Jan 12, 2026

Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
Ruthenium(II)-Catalyzed Macrocyclization via Site-Selective Hydroarylation of Alkynes: Access to Indoline-Braced
Abhishek Kumar Shaw1,2, Raziullah1, Anushka Rastogi1,2
1Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, Lucknow 226031, India.
Abstract:
Macrocycles are emerging as new therapeutic modalities in drug discovery. However, their efficient and diversity-oriented synthesis has significant challenges, as the conventional approaches often require conformationally flexible tethers and suitably functionalized termini for end-to-end coupling. In this regard, transition-metal-catalyzed C-H activation offers a potential solution. Here we report a Ru-catalyzed regioselective macrocyclization of Ar C(sp2)-H with an internal alkyne to afford macrocycles via the formation of a trisubstituted alkene. The method furnished indoline and other heteroarene-embedded cyclophanes of various ring sizes ranging from 13 to 23. The method is also applicable to various substrates that are tethered with quinols, carbohydrates, amino acids, and drug candidates.
More Related Videos
Related Concept Videos
Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Olefin Metathesis Polymerization: Overview
Ruthenium-based Grubbs catalyst is the most commonly used catalyst for olefin metathesis polymerization. Grubbs catalyst consists of a...
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.

