as documented by the clicking of carbohydrates with indolealkaloids. The method is also applicable to the conjugation of polymer chains. The linking acetal moiety can be readily cleaved and it is also shown that wavelength-selective coupling and cleavage with acyl silanes bearing a second photoactive moiety is possible. This is documented by a successful polymerization/depolymerization sequence and
A ruthenium-catalyzed [1,2]-Brook rearrangement involved dominosequence is presented to prepare highly functionalized silyloxy indenes with atomic- and step-economy. This domino reaction is triggered by acylsilane-directed C–H activation, and the aldehyde controlled the subsequent enol cyclization/Brook Rearrangement other than β–H elimination. The protocol tolerates a broad substitution pattern,
A ruthenium-catalyzed C–H alkenylation of aroylsilanes with electron-deficient alkenes was developed, using acylsilane as the directing group. The mild reaction conditions enable the tolerance of a wide scope of functionalities such as OMe, F, Cl, Br and CF3, providing a convenient and highly effective method for the synthesis of styrene derivatives bearing acylsilane. Steroid and heterocycles such
Brook Rearrangement as Trigger for Carbene Generation: Synthesis of Stereodefined and Fully Substituted Cyclobutenes
作者:Fa-Guang Zhang、Ilan Marek
DOI:10.1021/jacs.7b04255
日期:2017.6.21
Through a sequence that can be performed in a single vessel, involving regio- and diastereoselective copper-catalyzedcarbomagnesiation of cyclopropenes, reaction with acylsilanes, and addition of THF as cosolvent, Brook rearrangement can be triggered to furnish a wide range of cyclobutenes with exceptional diastereoselectivity. Accordingly, stereodefined and highly substituted cyclobutenes with contiguous
Visible-Light-Induced Catalyst-Free Carboxylation of Acylsilanes with Carbon Dioxide
作者:Zhengning Fan、Yaping Yi、Shenhao Chen、Chanjuan Xi
DOI:10.1021/acs.orglett.1c00435
日期:2021.3.19
Intermolecular carbon–carbon bond formation between acylsilanes and carbondioxide (CO2) was achieved by photoirradiation under catalyst-free conditions. In this reaction, siloxycarbenes generated by photoisomerization of the acylsilanes added to the C═O bond of CO2 to give α-ketocarboxylates, which underwent hydrolysis to afford α-ketocarboxylic derivatives in good yields. Control experiments suggest