81028-03-7Relevant articles and documents
Di- and tetrahydropyrans with orthogonally protected hydroxymethyl side chains: A synthetic route and the structure elucidation of an unexpected acetal cleavage product
Schmidt, Bernd,Pohler, Michael,Costisella, Burkhard
, p. 7951 - 7958 (2002)
A synthesis of dihydropyrans with orthogonally protected hydroxymethyl side chains is presented in this contribution. Key steps of the synthesis are the regioselective epoxide opening using vinyl cuprate reagents, selective protection of primary alcohols
Iridium-Catalyzed Regioselective Hydroalkynylation of Internal Alkenes Directed by an Oxime
Gao, Peng-Chao,Li, Bi-Jie,Wang, Zi-Xuan
supporting information, p. 9500 - 9504 (2021/12/14)
We report here an iridium-catalyzed hydroalkynylation of allylic alcohols protected by an oxime group. Catalytic alkynylation occurs exclusively at the distal position of the alkene. This method generates γ-alkynyl alcohol oximes directly from internal alkenes and terminal alkynes. The oxime group can be readily removed to afford a free alcohol, thus providing an indirect route for the catalytic hydroalkynylation of allylic alcohols.
Gold-Catalyzed Asymmetric Thioallylation of Propiolates via Charge-Induced Thio-Claisen Rearrangement
Kim, Hanbyul,Jang, Jiwon,Shin, Seunghoon
supporting information, p. 20788 - 20795 (2020/11/27)
A gold(I)-catalyzed enantioselective thioallylation of propiolates with allyl sulfides is described. The key mechanistic element is a sulfonium-induced Claisen rearrangement which helps minimize the allyl dissociation and render higher enantioselectivity. This protocol features remarkable scope of the allyl moiety, allowing enantiocontrolled synthesis of all-carbon quaternary centers, and exhibits exceptional functional group compatibility with many Lewis bases and π-bonds. This intermolecular variant of Claisen rearrangement forges both C-S and C-C bonds concomitantly, providing efficient access to interesting optically active organosulfur compounds which can be transformed further through the vinyl sulfide as a functional handle. The rate of the reaction was zeroth order with respect to allyl sulfides, which suggested a reversible inhibition, providing a resting state for the catalyst. The Hammett plot displayed a correlation with σp values, suggesting a turnover-limiting sigmatropic rearrangement where decreased electron-density on sulfur accelerated the rearrangement.
