Palladium-Catalyzed Decarboxylation of Allenyl 3-Oxoalkanoates: An Efficient Synthesis of 3,4-Allenyl Ketones
摘要:
An efficient synthesis of 3,4-allenyl ketones via the Pd-catalyzed decarboxylative coupling of the readily available 3-oxoalkanoates is reported. The C-C bond forming reaction occurs under mild conditions producing CO2 as the only byproduct.
Regio- and stereoselective hydrocyanation under nickel catalysis is described.
描述了在镍催化下的区域和立体选择性氢氰化。
Dynamic Kinetic Asymmetric Allylic Alkylations of Allenes
作者:Barry M. Trost、Daniel R. Fandrick、Diana C. Dinh
DOI:10.1021/ja0543705
日期:2005.10.1
The dynamic kineticasymmetricallylicalkylations of racemic allene acetates has been developed with the DACH−phenyl Trost ligand 2 to give general access to allenes with high enantiomeric excess (84−95%) for both malonate and amine nucleophiles. Further, a most unusual dependence of enantioselectivity on base has been uncovered. The magnitude of the enantioselectivity is heavily dependent on the
Vinyl-substituted (Z)-stilbenes are stereoselectively synthesised on treatment of 4-arylbuta-2,3-dien-1-ols with arylboronic acids in the presence of a rhodium(I) catalyst. The reaction proceeds through the regioselective addition of organorhodium(I) species across the aryl-substituted carbon–carbon double bond of the allene moiety and subsequent δ-elimination of Rh(I)–OH.
Rhodium‐Catalyzed Dynamic Kinetic [4+2] Cycloaddition of Allene‐1,3‐Dienes
作者:Yulin Han、Anni Qin、Qian Zhang、Xue Zhang、Hui Qian、Shengming Ma
DOI:10.1002/anie.202211635
日期:2022.11.21
A rhodium/Malphos catalytic recipe has been developed for the dynamic kinetic intramolecular Diels–Aldercycloaddition of allene-1,3-dienes. The desired cis-fused [4.3.0]bicyclic products were obtained with decent yields and excellent stereo- and enantioselectivity. Its dynamic kinetic nature has been confirmed by careful mechanistic studies.
Substitution of P(O)Ph2, SOPh and SO2Ph on an allene facilitates intramolecular radical addition to the central allene carbon to provide good yields of five-, six-, and seven-membered carbocycles.