C-H Insertion via Ruthenium Catalyzed gem-Hydrogenation of 1,3-Enynes was written by Peil, Sebastian;Gutierrez Gonzalez, Alejandro;Leutzsch, Markus;Fuerstner, Alois. And the article was included in Journal of the American Chemical Society in 2022.Electric Literature of C12H15NO3S This article mentions the following:
Gem-Hydrogenation of an internal alkyne with the aid of [Cp*RuCl]4 as the precatalyst is a highly unorthodox transformation, in which one C atom of the triple bond is transformed into a methylene group, whereas the second C atom gets converted into a ruthenium carbene. In the case of 1,3-enynes bearing a propargylic steering substituent as the substrates, the reaction occurs regioselectively, giving rise to vinyl carbene complexes that adopt interconverting η1/η3-binding modes in solution; a prototypical example of such a reactive intermediate was characterized in detail by spectroscopic means. Although both forms are similarly stable, only the η3-vinyl carbene proved kinetically competent to insert into primary, secondary, or tertiary C-H bonds on the steering group itself or another suitably placed ether, acetal, orthoester, or (sulfon)amide substituent. The ensuing net hydrogenative C-H insertion reaction is highly enabling in that it gives ready access to spirocyclic as well as bridged ring systems of immediate relevance as building blocks for medicinal chem. Moreover, the reaction scales well and lends itself to the formation of partly or fully deuterated isotopologues. Labeling experiments in combination with PHIP NMR spectroscopy (PHIP = parahydrogen induced polarization) confirmed that the reactions are indeed triggered by gem-hydrogenation, whereas kinetic data provided valuable insights into the very nature of the turnover-limiting transition state of the actual C-H insertion step. In the experiment, the researchers used many compounds, for example, 1-Tosylpiperidin-4-one (cas: 33439-27-9Electric Literature of C12H15NO3S).
1-Tosylpiperidin-4-one (cas: 33439-27-9) belongs to piperidine derivatives. Piperidine is a metabolite of cadaverine, a polyamine found in the human intestine. Some chemotherapeutic agents have piperidine moiety within their structure, foremost among them, vinblastine and raloxifene.Electric Literature of C12H15NO3S
Referemce:
Piperidine – Wikipedia,
Piperidine | C5H11N – PubChem