31491-20-0Relevant articles and documents
Enantioselective Copper-Catalyzed Radical Ring-Opening Cyanation of Cyclopropanols and Cyclopropanone Acetals
Chen, Pinghong,Guo, Yin-Long,Liu, Guosheng,Wang, Lei,Wu, Lianqian
supporting information, p. 2189 - 2194 (2020/04/17)
A novel approach for enantioselective cyanation of cyclopropanols and their derivatives through copper-catalyzed radical relay processes has been developed. Various cyclopropanols and cyclopropanone acetals are compatible to the catalytic conditions, providing β-carbonyl nitriles with excellent enantioselectivity. These products can be readily converted to chiral γ-amino acids derivatives and drugs such as (R)-baclofen. Preliminary mechanistic studies have supported a ring-opening process for cyclopropanoxy radicals followed by copper-catalyzed enantioselective cyanation of benzylic radicals to form the C?CN bonds in an enantioselective manner. (Figure presented.).
Mechanistic studies on α-trifluoromethylation of ketones via silyl enol ethers and its application to other carbonyl compounds
Sato, Kazuyuki,Yuki, Takashi,Yamaguchi, Ryoji,Hamano, Tetsuya,Tarui, Atsushi,Omote, Masaaki,Kumadaki, Itsumaro,Ando, Akira
supporting information; experimental part, p. 3815 - 3819 (2009/10/01)
(Chemical Equation Presented) Synthesis of α-CF3 carbonyl compounds has been recognized to be difficult up to now because the polarization of CF3δ--Iδ+ is opposite to that of CH3δ+-Iδ-, and this makes it difficult to introduce CF3+ unit to enolates. We recently reported an effective R-trifluoromethylation of ketones by using Et 2Zn with Rh catalyst, but the mechanism has not fully been cleared. Now, we carried out the detailed mechanistic studies and found the involvement of a highly reactive alkylrhodium complex which derived from Et2Zn and RhCl(PPh3)3 in this α-trifluoromethylation. Furthermore, this α-trifluoromethylation was applied to other types of carbonyl compounds in good yields.
Oxidation of Alkyl Trimethylsilyl Ketene Acetals with Lead(IV)
Rubottom, George M.,Gruber, John M.,Marrero, Roberto,Juve, Henrik D.,Kim, Wan Chong
, p. 4940 - 4944 (2007/10/02)
Alkyl trimethylsilyl ketene acetals generated from either esters or lactones react with lead(IV) acetate (LTA) or lead(IV) benzoate (LTB) to afford useful yields of the corresponding α-carboyloxy esters and α-carboyloxy lactones.Yields of the reaction products are optimized by use of the appropriate solvent (methylene chloride or benzene) during oxidation.Alkyl groups such as methyl, ethyl, and tert-butyl are all compatible with the procedure, and lactones containing five-, six-, and seven-membered rings give good yields of oxidation products.
