655-48-1Relevant articles and documents
Stereospecific and regioselective reactions of silacyclopropanes with carbonyl compounds catalyzed by copper salts: Evidence for a transmetalation mechanism
Franz, Annaliese K.,Woerpel
, p. 949 - 957 (1999)
Silacyclopropanes reacted with carbonyl compounds under mild conditions (10 mol % metal salt, ≤22 °C) in a stereospecific and highly stereo-, regio-, and chemoselective fashion. In most cases, CuI or CuBr2 were the optimal catalysts although ZnBr2 worked comparably well in a few examples. Insertion occurred with retention of configuration and, in the case of enals and formamides, with high diastereoselectivity at the newly formed stereogenic centers. For unsymmetrical substrates, insertion occurred at the more substituted carbon-silicon bond with complete regioselectivity. Competition experiments demonstrated that formamides reacted faster than enals, which reacted faster than enoates; saturated aldehydes did not undergo insertion. With a cis-disubstituted silacyclopropane, products of silylene transfer were observed. The stereochemistry, regiochemistry, and chemoselectivity of carbonyl insertion as well as the silylene transfer processes can be explained by a mechanism involving transmetalation of silicon to copper.
Mo–Catalyzed One-Pot Synthesis of N-Polyheterocycles from Nitroarenes and Glycols with Recycling of the Waste Reduction Byproduct. Substituent-Tuned Photophysical Properties
Hernández-Ruiz, Raquel,Rubio-Presa, Rubén,Suárez-Pantiga, Samuel,Pedrosa, María R.,Fernández-Rodríguez, Manuel A.,Tapia, M. José,Sanz, Roberto
supporting information, p. 13613 - 13623 (2021/08/23)
A catalytic domino reduction–imine formation–intramolecular cyclization–oxidation for the general synthesis of a wide variety of biologically relevant N-polyheterocycles, such as quinoxaline- and quinoline-fused derivatives, and phenanthridines, is reported. A simple, easily available, and environmentally friendly dioxomolybdenum(VI) complex has proven to be a highly efficient and versatile catalyst for transforming a broad range of starting nitroarenes involving several redox processes. Not only is this a sustainable, step-economical as well as air- and moisture-tolerant method, but also it is worth highlighting that the waste byproduct generated in the first step of the sequence is recycled and incorporated in the final target molecule, improving the overall synthetic efficiency. Moreover, selected indoloquinoxalines have been photophysically characterized in cyclohexane and toluene with exceptional fluorescence quantum yields above 0.7 for the alkyl derivatives.
Metal-free thermal organocatalytic pinacol coupling of arylaldehydes using an isonicotinate catalyst with bis(pinacolato)diboron
Hanaya, Kengo,Higashibayashi, Shuhei,Sugai, Takeshi,Yasui, Masamichi
, p. 24652 - 24655 (2021/07/29)
The metal-free thermal organocatalytic pinacol coupling of arylaldehydes has been developed. The intermolecular coupling of arylaldehydes catalyzed byt-butyl isonicotinate with bis(pinacolato)diboron as the co-reducing agent afforded 1,2-diphenylethane-1,2-diols. This reaction was also applicable to the intramolecular coupling of 1,1′-biphenyl-2,2′-dicarbaldehydes to afford 9,10-dihydrophenanthrene-9,10-diols. Various functional groups were tolerated under this coupling condition.