RESUMO
Copper-catalyzed divergent conjugate protosilylation and protoborylation of polar enynes were developed. The corresponding ß-boryldienoates and ß-silyldienotes were obtained in moderate to good yields and with good stereoselectivity. In this protocol, novel cascade double protoborylation/protodeboronation processes of polar enynoates enabled access of the useful trisubstituted vinylboronates in up to 80% yield and with up to 98:2 Z/ E ratio. Moreover, divergent transformations of the products thus obtained were also investigated.
RESUMO
A general strategy for the hydroalkylation of vinyl ketones using ethers catalyzed by an iron catalyst is described. This catalytic method permits direct transformation of easily accessible and abundant precursors into highly substituted, structurally diverse and functionally concentrated products.
RESUMO
A hydroxy group chelation-assisted stereospecific oxidative cross-coupling reaction between alkenes was developed under mild reaction conditions. In the presence of palladium catalyst, the alkenes tethered with hydroxy functionality can couple efficiently with electron-deficient alkenes to form the corresponding multi-substituted olefin products. The hydroxy group on the substrate could play dual roles in reaction, acting as the directing group for alkenyl C-H bond activation and controlling the stereoselectivity of the products.
RESUMO
A palladium-catalyzed intramolecular amination of alkenes with retention of olefin functionalization was achieved under mild reaction conditions. In the presence of palladium catalyst, the tosyl-protected amine can directly couple with a double bond to provide versatile dihydropyrrole derivatives in moderate to excellent yields.
RESUMO
Lewis acid B(C6F5)3 catalyzed the Diels-Alder reactions of multisubstituted open-chain dienes and α,ß-enals to afford the desired products with high exo-selectivities are reported. The substituent effect of the dienes and dienophiles on the product's stereoselectivity was thoroughly investigated, and it was found that most of the desired exo-Diels-Alder products could be obtained in good yields and with high exo-stereoselectivities.