A dirhodium-catalyzed, β-selective C-H amination of organosilicon compounds has been developed. Primary C(sp3)-H bonds of silylethyl groups and secondary C(sp3)-H bonds of silacycloalkanes can be selectively converted to C-N bonds at the β-position of the silicon atoms. The experimental data and theoretical calculations indicate that the strong σ-donor ability of the carbon-silicon bonds is responsible
Desymmetrisation and ring opening of cyclohexa-1,4-dienes. An access to highly functionalised cyclic and acyclic systems
作者:Yannick Landais、Elisabeth Zekri
DOI:10.1016/s0040-4039(01)01318-1
日期:2001.9
Acyclic and cyclic synthons are readily available in three steps starting from substituted arenes. Birch reduction of the latter followed by desymmetrisation through Sharpless AD reaction then ozonolysis thus afforded five-membered ring lactols and acyclic polyols with good to excellent stereocontrol in high yields.
A straightforwardroute to polyols, amino polyols, polysubstituted lactols and lactones from readily available arenes has been devised. It uses a three- or four-step sequence involving a Birch reduction of the arene, followed by desymmetrization through dihydroxylation or aminohydroxylation and, lastly, ozonolysis of the remaining olefin. Depending on the ozonolysis workup conditions, cyclic or acylic
Catalytic <i>ipso</i>‐Nitration of Organosilanes Enabled by Electrophilic <i>N</i>‐Nitrosaccharin Reagent
作者:Ivan Mosiagin、Anthony J. Fernandes、Alena Budinská、Liana Hayriyan、Kai E. O. Ylijoki、Dmitry Katayev
DOI:10.1002/anie.202310851
日期:2023.10.9
Deploying N-nitrosaccharin reagents in combination with Lewis acid activation enables the facile, regio- and chemoselective nitration of (het)aryl silanes, allowing the introduction of nitro group under unprecedently mild conditions suitable for the late-stage nitration of complex and polyfunctionalized molecules. Theoretical and experimental mechanistic investigations formulate a plausible mechanism
Sterically Controlled Isodesmic Late-Stage C–H Iodination of Arenes
作者:Manuel van Gemmeren、Mirxan Farizyan、Rita de Jesus、Jyotirmoy Dey
DOI:10.1039/d3sc00801k
日期:——
availability of the required starting materials. Herein, we describe the sterically controlled iodination of arenes through an isodesmic C–H/C–I bond metathesis approach enabled by our dual ligand-based catalysts for arene-limited nondirected C–H activation. The protocol gives direct access to a complementary product spectrum with respect to traditional methods. Its synthetic utility is demonstrated by