13757-03-4Relevant articles and documents
Gold-Catalyzed Synthesis of Chiral Cyclopentadienyl Esters via Chirality Transfer
Zhao, Ke,Hsu, Yu-Chen,Yang, Ziguang,Liu, Rai-Shung,Zhang, Liming
, p. 6500 - 6504 (2020)
Efficient access to chiral cyclopentadienyl esters from readily accessible chiral enynyl ester substrates is developed. Typically high levels of chirality transfer realized in this homogeneous gold catalysis are attributed to the intermediacy of a chiral bent allene gold complex. Cyclopentadienyl esters can be prepared in good yields and with excellent enantiomeric excesses. The synthetic utilities of the chiral cyclopentadienyl esters are demonstrated by the Diels-Alder reactions, fluorination, alkylation, and epoxidation without any notable erosion of enantiopurity.
Direct synthesis of pyrazoles from esters using tert-butoxide-assisted C-(C=O) coupling
Kim, Bo Ram,Sung, Gi Hyeon,Ryu, Ki Eun,Lee, Sang-Gyeong,Yoon, Hyo Jae,Shin, Dong-Soo,Yoon, Yong-Jin
supporting information, p. 9201 - 9204 (2015/06/08)
This paper describes the direct synthesis of pyrazoles from esters that comprises two sequential reactions: tert-butoxide-assisted C-C(=O) coupling reaction to yield β-ketonitrile or α,β-alkynone intermediates, and condensation by hydrazine addition. The method reported allows for easy control of the regioselectivity and structure of substituents at N-1, C-3, C-4 and/or C-5 positions.
Efficient methods for the preparation of acetylenic ketones
Verkruijsse, H. D.,Heus-Kloos, Y. A.,Brandsma, I.
, p. 289 - 294 (2007/10/02)
A number of acetylenic ketones RCCC(=O)R' have been obtained in good yields from lithiated acetylenes RCCLi and acetic anhydride, N,N-dimethylacetamide, or N,N-dimethylbenzamide.The most convenient and general method consists of treating alkynylzinc chlorides with acid halides R'C(=O)Cl.Benzoyl chloride (R'=Ph), acryloyl chloride (R'=CH2=CH) and butynoyl chloride (R'=C2H5CC) react only in the presence of a catalytic amount of Pd4.
