19780-94-0Relevant articles and documents
Kawasaki,I.,Kaneko,T.
, p. 1482 (1968)
Towards quantitative and scalable transformation of furfural to cyclopentanone with supported gold catalysts
Zhang, Gao-Shuo,Zhu, Ming-Ming,Zhang, Qi,Liu, Yong-Mei,He, He-Yong,Cao, Yong
, p. 2155 - 2164 (2016/04/19)
Given the vital importance of furfural (FFA) upgrading towards a sustainable bio-based economy, an eco-friendly aqueous route to produce a sole valuable product from FFA is highly desirable. We herein describe an efficient approach to quantitatively convert FFA into cyclopentanone (CPO) in neat water, employing H2 as the clean reductant and supported gold nanoparticles as a simple yet versatile catalyst. The use of anatase TiO2 featuring only mild Lewis acidic sites as the underlying support is essential, not only for preventing undesirable side reactions, but also for attaining high CPO selectivity. The feasibility of using biogenic CPO and CO2 as benign carbon sources to synthesize the industrially important feedstock dimethyl adipate is also demonstrated.
Palladium(II)-catalyzed oxidation of aldehydes and ketones. 1. Carbonylation of ketones with carbon monoxide catalyzed by palladium(II) chloride in methanol
Hamed,El-Qisairi,Henry
, p. 180 - 185 (2007/10/03)
Unsubstituted or alkyl-substituted cyclic ketones react with PdCl2 in methanol under a CO atmosphere to give mainly acyclic diesters along with some acyclic chloro-substituted monoesters. The monosubstituted cyclic ketones, 2-hydroxy- and 2-methoxycyclohexanone, do not give ring cleavage but rather produce 2-(carbomethoxy)cyclohex-2-en-1-one. 13CO labeling experiments indicate one CO is inserted in forming the diester product so the second ester group must arise from the original ketone group. Two mechanisms are possible for the diester reaction. One involves initial Pd(II)-CO2CH3 insertion across the double bond of the enol form of the ketone while the second involves initial addition of Pd(II)-OCH3 followed by CO insertion into the new Pd(II) carbon bond formed. Pd(II) elimination and acid-catalyzed ring cleavage produce the second methyl ester group in both routes. The chloro-substituted monoester is formed by initial Pd(II)-Cl insertion across the double bond followed by the acid-catalyzed ring cleavage. The 2-(carbomethoxy)cyclohex-2-en-1-one must result from elimination of water or methanol from the α-ketoester product formed by the initial methoxycarbonylation of the enol form of the ketone. As expected, the acyclic ketone 2-decanone, formed methyl acetate and a mixture of methyl nonanoate and products.
Asymmetric Synthesis of 3-Substituted 2-exo-Methylenealkanones by Addition-Elimination Reaction Using a Chiral Leaving Group and Organometallic Nucleophiles
Tamura, Rui,Watabe, Ken-ichiro,Ono, Noboru,Yamamoto, Yukio
, p. 4895 - 4903 (2007/10/02)
A novel diastereodifferentiating addition-elimination reaction of (S)-2-methyl>-2-alken-1-ones with organometallic reagents such as organocuprates and organozincates afforded optically active 3-substituted 2-methylenealkanones with high enantiomeric purity.The enantiomeric excess (ee) of the products in this asymmetric induction reaction involving 1,5-transfer of stereogenicity was highly dependent on the structure of the enone substrates and the type of organometallic reagents, chiral auxiliaries, and added Lewis acids: (i) the use of lithium diorganocuprates (R2CuLi) led to the highest ee's, (ii) in the reaction with R2CuLi the ee decreased in the following order by varying their structure of the main framework of the enones, cycloheptenones (96-97 percent ee) > cyclohexenones ( 95 percent ee) > cyclopentenones ( 82-85 percent ee) > acyclic enones (55-70 percent ee), (iii) the addition of LiBr as the external Lewis acid in the reaction with R2CuLi did not affect the ee, whereas that of ZnBr2 or MgBr2 decreased the ee by 5 percent or considerably more, respectively, and (iv) the existence of the methoxy oxygen atom in the chiral auxiliary was essential to achieve high ee's.The origin of the observed high and low ee's was rationalized by considering plausible transition state models.
