81798-12-1Relevant articles and documents
Metal-Free sp3 C-SCF3 Coupling Reactions between Cycloketone Oxime Esters and S-trifluoromethyl 4-Methylbenzenesulfonothioate
Zhao, Xia,Tian, Miaomiao,Ji, Liangshuo,Liu, Junjie,Lu, Kui
, p. 863 - 866 (2020)
A novel sp3 C-SCF3 coupling reaction between cycloketone oxime esters and S-trifluoromethyl 4-methylbenzenesulfonothioate was achieved. Ethanol was found to facilitate this transformation by trapping the sulfonyl cation. The metal-free and photocatalyst-free reaction conditions, as well as the broad substrate scope, make this a green protocol for the synthesis of SCF3-substituted nitriles.
Nickel-Catalyzed Favorskii-Type Rearrangement of Cyclobutanone Oxime Esters to Cyclopropanecarbonitriles
Fang, Ping,Mei, Tian-Sheng,Shuai, Bin
supporting information, p. 1637 - 1641 (2021/10/02)
A nickel-catalyzed base-promoted rearrangement of cyclobutanone oxime esters to cyclopropanecarbonitriles was developed. The ring opening of cyclobutanone oxime esters occurs at the sterically less hindered side. A base-promoted nickelacyclobutane intermediate, formed in situ, is assumed to be involved in the formation of the product.
Nucleophilic substitutions of 1-alkenylcyclopropyl esters and 1-alkynylcyclopropyl chlorides catalyzed by palladium(0)
Stolle, Andreas,Ollivier, Jean,Piras, Pier Paolo,Salaün, Jacques,De Meijere, Armin
, p. 4051 - 4067 (2007/10/02)
The 1-ethenylcyclopropylsulfonates 2e,f and 2-cyclopropylideneethyl esters 10b,c, readily available from cyclopropanone hemiacetal 1, undergo regioselective Pd(0) catalyzed nucleophilic substitution via the unsymmetric 1,1-dimethylene-π-allyl complex 23. With stabilized anions (enolates of malonic ester, β-dicarbonyl compounds, β-sulfonyl ester, and Schiff bases as well as acetate anion, sulfonamide anion, etc.) the nucleophilic substitution occurs at the terminal vinylic position exclusively, providing cyclopropylideneethyl derivatives as building blocks of high synthetic potential. Competition experiments have disclosed that 1-ethenylcyclopropyl tosylate (2e) and cyclopropylideneethyl acetate (10b) are more reactive than dimethylallyl acetates 19 and 22, respectively. Use of chiral phosphines as ligands in the palladium catalyst can provide optically active methylenecyclopropane derivatives. With phenyl-, methyl-, and even n-butylzinc chloride as nucleophiles, the reaction apparently proceeds with initial transfer of the organic residue to palladium, followed by reductive elimination entailing tertiary substitution on the cyclopropane ring exclusively; the same type of product is obtained with azide and bis(trimethylsilyl)amide. But the site of hydride attack to yield reduction products depends on the hydride source. 1-Alkynylcyclopropyl chlorides 12, 13, and 14 react only with organozinc chlorides (nonstabilized nucleophiles) to provide mixtures of ethenylidenecyclopropanes 65 and alkynylcyclopropanes 66, via the σ-palladium complexes 69 and 70, while chloride 15 undergoes mainly reduction. Other transition metal catalysts (Ni, Mo) also induce substitutions, but with poorer regioselectivity.
