69063-22-5Relevant articles and documents
Pd-complex-bound amino acid-based supramolecular gel catalyst for intramolecular additioncyclization of alkynoic acids in water
Ogata, Kazuki,Sasano, Daisuke,Yokoi, Tomoya,Isozaki, Katsuhiro,Seike, Hirofumi,Takaya, Hikaru,Nakamura, Masaharu
, p. 498 - 500 (2012)
An NCN-pincer Pd-complex-bound norvaline-based supramolecular gel showed efficient catalytic activities for the intramolecular additioncyclization of alkynoic acid and phenol derivatives in water to afford the corresponding ene-lactones in good to excelle
Regioselectivity Influences in Platinum-Catalyzed Intramolecular Alkyne O-H and N-H Additions
Costello, Jeff P.,Ferreira, Eric M.
, p. 9934 - 9939 (2019/12/24)
The steric and electronic drivers of regioselectivity in platinum-catalyzed intramolecular hydroalkoxylation are elucidated. A branch point is found that divides the process between 5-exo and 6-endo selective processes, and enol ethers can be accessed in good yields for both oxygen heterocycles. The main influence arises from an electronic effect, where the alkyne substituent induces a polarization of the alkyne that leads to preferential heteroatom attack at the more electron-deficient carbon. The electronic effects are studied in other contexts, including hydroacyloxylation and hydroamination, and similar trends in directionality are predominant although not uniformly observed.
Impregnated palladium on magnetite as a water compatible catalyst for the cycloisomerization of alkynoic acid derivatives
Saavedra, Beatriz,Pérez, Juana M.,Rodríguez-álvarez, María J.,García-álvarez, Joaquín,Ramón, Diego J.
, p. 2151 - 2157 (2018/05/23)
This work describes the catalytic activity of palladium(ii) species in the cycloisomerization of alkynoic acids and their derivatives in aqueous media as well as in Deep Eutectic Solvents (DESs), with one of the lowest metal catalyst loadings reported so far in the literature. Different substrates such as terminal and internal alkynes or alkynyl sulfonylimides were studied, obtaining selectivity either to the cyclic compound or the hydrolysed keto derivative. This new system avoids the use of harmful solvents and employs very efficient and recoverable heterogeneous catalysts.
