Double 1,4-rhodium migration cascade in rhodium-catalysed arylative ring-opening/spirocyclisation of (3-arylcyclobutylidene)acetates
作者:Takanori Matsuda、Yuya Suda、Akira Takahashi
DOI:10.1039/c2cc18098g
日期:——
1,4-Rhodium migration occurs twice during the course of the rhodium-catalysed arylative ring-opening/spirocyclisation reaction of (3-arylcyclobutylidene)acetates with sodium tetraarylborates to afford ketones possessing a 1,1′-spirobiindane skeleton.
Phenyl(trimethylsilyl)ketene. Some ketene reactions with diazomethane
作者:William T Brady、Theresa C Cheng
DOI:10.1016/s0022-328x(00)81435-7
日期:1977.9
Phenyl(trimethylsilyl)ketene was prepared by the zinc dehalogenation of phenyl(trimethylsilyl)bromoacetyl chloride. This ketene parallels tirmethylsilylketene in stabibility and lack of reactivity in cycloaddition reactions. The reaction of phenyl(ethyl)-, phenyl(trimethylsilyl)- and trimethylsilylketenes with diazomethane at −78°C is described. Only the 21 cycloadducts, the cyclobutanones, could be
Enantioselective Synthesis of Indanols from tert-Cyclobutanols Using a Rhodium-Catalyzed CC/CH Activation Sequence
作者:Tobias Seiser、Olivia A. Roth、Nicolai Cramer
DOI:10.1002/anie.200903189
日期:——
Activation! An enantioselective activation of tert‐cyclobutanols by a chiral rhodium(I) complex has been developed. The resulting reactive organometallic species lead (presumably by a CHactivation pathway) to aryl rhodium intermediates that provide substituted indanol derivatives in excellent enantio‐ and diastereoselectivities (see scheme).
The chemodivergent ring-opening of cyclobutanols is described under the carbocatalytic assistance of grapheneoxide (GO). The protocol enables the synthesis of diversely functionalized dienes or indenes (26 examples) based on the amount of GO employed. Spectroscopic (XPS and ssNMR) as well as experimental investigations revealed a direct involvement of the π-domains of GO in tuning the stability of
The palladium-catalyzed skeletal rearrangement of 3-arylcyclobutanones into 1-indanones is reported. A Pd(0)/IMes catalyst allows for the cleavage of C(carbonyl)–C(sp3) and C(sp2)–H bonds to result in the skeletal rearrangement, and neither an extra reactive functional group nor a directing group is required to promote the reaction. Deuterium-labeling experiments indicate that the C–C bond is initially