930-30-3Relevant articles and documents
Synthesis of functionalized olefins by cross and ring-closing metatheses [7]
Chatterjee, Arnab K.,Morgan, John P.,Scholl, Matthias,Grubbs, Robert H.
, p. 3783 - 3784 (2000)
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Independent generation of triplet 1,4-biradical intermediates implicated in the photochemical cycloaddition reaction between 2-cyclopentenone and acrylonitrile
Krug,Rudolph,Weedon
, p. 7221 - 7224 (1993)
Norrish Type 1 photochemistry of 3-cyanobicyclo[3.3.0]octane-2,6-dione and 3-cyanobicyclo[3.3.0]octane-2,8-dione is used to generate triplet 1,4-biradicals implicated in the photochemical cycloaddition reaction of 2-cyclopentenone with acrylonitrile. The fates of these biradicals have been determined and they suggest that the photocycloaddition reaction regiochemistry is governed by competition between closure of the biradicals to product and their reversion to ground state starting materials. This provides further evidence against the long-held view that the relative rates of formation of the biradicals mediated by an oriented triplet exciplex governs the reaction regiochemistry. It is also found that the regiochemistry of the photochemical cycloaddition reaction between cyclopentenone and acrylonitrile is reversed from that obtained in the addition of acrylonitrile to 2-cyclohexenone.
g-C3N4/metal halide perovskite composites as photocatalysts for singlet oxygen generation processes for the preparation of various oxidized synthons
Corti, Marco,Chiara, Rossella,Romani, Lidia,Mannucci, Barbara,Malavasi, Lorenzo,Quadrelli, Paolo
, p. 2292 - 2298 (2021/04/12)
g-C3N4/metal halide perovskite composites were prepared and used for the first time as photocatalysts forin situ1O2generation to perform hetero Diels-Alder, ene and oxidation reactions with suitable dienes and alkenes. The standardized methodology was made applicable to a variety of olefinic substrates. The scope of the method is finely illustrated and the reactions afforded desymmetrized hydroxy-ketone derivatives, unsaturated ketones and epoxides. Some limitations were also observed, especially in the case of the alkene oxidations, and poor chemoselectivity was somewhere observed in this work which is the first application of MHP-based composites forin situ1O2generation. The experimental protocol can be used as a platform to further expand the knowledge and applicability of MHPs to organic reactions, since perovskites offer a rich variety of tuning strategies which may be explored to improve reaction yields and selectivities.
A gradient reduction strategy to produce defects-rich nano-twin Cu particles for targeting activation of carbon-carbon or carbon-oxygen in furfural conversion
An, Zhe,Guo, Shaowei,He, Jing,Ma, Xiaodan,Shu, Xin,Song, Hongyan,Xiang, Xu,Zhang, Jian,Zhu, Yanru
, p. 78 - 86 (2020/06/21)
Complexity of chemical linkages (C-C/C-H/C-O, C=C/C=O, or C-O-H/C-O-C) in biomass-derived molecules makes the selective activation of targeted bonds much more challenging, expecting well-defined catalysts and definite catalytically-active sites. This work demonstrates an effective gradient reduction strategy to control the definite structure of catalytically-active sites, affording defects-rich nano-twin Cu particles. This strategy just involves the reduction (calcination under H2) of CuII-containing layered double hydroxides (LDHs) simply with controlling the reduction gradient (interval time) of CuII species in two chemical micro-environments (CuII-O-CuII and CuII-O-MII/III/IV (M ≠ Cu)) in the brucite-like layer of LDHs. The nano-twin Cu particles efficiently promote the target activation of C-O and C=C in the conversion of furfural to cyclopentanone (CPO). With ~100% furfural conversion, the defects-rich nano-twin Cu particles afford a CPO selectivity of 92%, 50% higher than regular spherical Cu particles. The multi-stepped defect sites, originating from the planar defects, play a decisive role in promoting the CPO selectivity by facilitating the hydro-deoxygenation to C-O of 4-hydroxycyclopentenone (HCP) and hydrogenation to C=C of HCP or cyclopentenone.