1060751-37-2Relevant academic research and scientific papers
Cleavage of acetylenic substituents from camphor-derivatives by copper(I) chloride
Carvalho,Fernandes,Ferreira,Alves,Herrmann
, p. 2847 - 2855 (2008)
Copper(I) chloride was found to be a highly efficient reagent to promote the cleavage of acetylenic substituents from the camphor skeleton of compounds 1 containing two C-C triple bonds as well as from the compounds 6 and 7 containing one. This is a formal reversal of the formation of these compounds by the reaction of acetylides with keto and imino groups in compound 18. The substituent R at the triple bond modifies the reactivity and regioselectivity. As intermediates in the process we identified complexes of the types [Cu(L)depr] (where (L)depr denotes a deprotonated camphor-derived ligand (L)) and [CuCl(L)]. Quantum mechanical calculations support and rationalize the experimental results.
Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds
Carvalho, M. Fernanda N. N.,Herrmann, Rudolf,Wagner, Gabriele
, p. 1230 - 1238 (2017)
Compounds containing two alkyne groups in close vicinity at the rigid skeleton of camphorsulfonamide show unique reactivities when treated with electrophiles or catalytic amounts of platinum(II). The formed product structures depend not only on the reagents used but also on the substituents attached to the triple bonds. Cycloisomerisations with perfect atom economy lead to polycyclic heterocycles that resemble to some extent the AB ring system of paclitaxel. Herein, we present practical synthetic methods for the selective synthesis of precursor dialkynes bearing different substituents (alkyl, aryl) at the triple bonds, based on ketals or an imine as protecting groups. We show for isomeric dialkynes that the reaction cascade induced by Pt(II) includes ring annulation, sulphur reduction, and ring enlargement. One isomeric dialkyne additionally allows for the isolation of a pentacyclic compound lacking the ring enlargement step, which we have proposed as a potential intermediate in the catalytic cycle.
