163615-17-6Relevant articles and documents
Radical trifluoromethylation of ketone silyl enol ethers by activation with dialkylzinc
Mikami, Koichi,Tomita, Yuichi,Ichikawa, Yoshiyuki,Amikura, Kazutoshi,Itoh, Yoshimitsu
, p. 4671 - 4673 (2006)
(Chemical Equation Presented) The radical trifluoromethylation of ketone silyl enol ethers gave α-CF3 ketones in good yields with wide scope of the ketonic substrates including acyclic ketones and cyclopentanone. The use of dialkylzinc to activ
Zincate-type enolate for radical α-trifluoromethylation
Tomita, Yuichi,Ichikawa, Yoshiyuki,Itoh, Yoshimitsu,Kawada, Kosuke,Mikami, Koichi
, p. 8922 - 8925 (2007)
Ketone zincate-type enolates can be applied to radical trifluoromethylation for the general synthesis of α-CF3-ketones, cyclopentanones in particular. The addition of diethylzinc to lithium enolates is the key in the preparation of the zincate-
Dialkylzinc-aceelerated α-trifluoromethylation of carbonyl compounds catalyzed by late-transition-metal complexes
Tomita, Yuichi,Itoh, Yoshimitsu,Mikami, Koichi
, p. 1080 - 1081 (2008)
Trifiuoromethylation of ketone silyl enol ethers is found to be significantly accelerated by late-transition-metal catalysts and dialkylzincs to give α-trifluoromethyl ketones in good yields. Addition of dialkylzinc is the key to the high yielding α-trifl
Radical trifluoromethylation of Ti ate enolate: possible intervention of transformation of Ti(IV) to Ti(III) for radical termination
Itoh, Yoshimitsu,Mikami, Koichi
, p. 539 - 544 (2006)
The radical trifluoromethylation of ketone Ti ate enolates gave α-CF3 ketones in good yields. The use of excess amount of LDA and Ti(OiPr)4 in the preparation of Ti ate enolates is the key to the efficient radical trifluor
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.
Zn-mediated rhodium-catalyzed α-trifluoromethylation of ketones via silyl enol ethers
Sato, Kazuyuki,Yuki, Takashi,Tarui, Atsushi,Omote, Masaaki,Kumadaki, Itsumaro,Ando, Akira
, p. 3558 - 3561 (2008/09/21)
The treatment of silyl enol ethers of ketones with CF3-I and Et2Zn in the presence of RhCl(PPh3)3 in DME gave α-trifluoromethyl ketones in good yields. The reaction can be widely applicable to silyl enol ethers
Radical trifluoromethylation of ketone Li enolates
Itoh, Yoshimitsu,Mikami, Koichi
, p. 7199 - 7203 (2007/10/03)
It has generally been believed that highly basic Li enolates cannot be applied as substrates for radical trifluoromethylation due to defluorination of the α-CF3 product. However, Li enolates can be in fact employed for radical trifluoromethylat
Radical trifluoromethylation of titanium ate enolate
Itoh, Yoshimitsu,Mikami, Koichi
, p. 649 - 651 (2007/10/03)
(Chemical Equation Presented) The radical trifluoromethylation of ketone titanium ate enolates gave α-CF3 ketones in good yields. The use of excess amount of LDA and Ti(OiPr)4 in the preparation of titanium ate enolates is
Facile radical trifluoromethylation of lithium enolates
Itoh, Yoshimitsu,Mikami, Koichi
, p. 4883 - 4885 (2007/10/03)
(Chemical Equation Presented) Highly basic lithium enolates are shown to be applicable to radical trifluoromethylation. The reaction is extremely fast, and the minimum reaction time is ~1 s.
New Method for Trifluoromethylation of Enolate Anions and Applications to Regio-, Diastereo- and Enantioselective Trifluoromethylation
Umemoto, Teruo,Adachi, Kenji
, p. 5692 - 5699 (2007/10/02)
Assessment was made of the effectiveness of different boron Lewis acids in mediating the trifluoromethylation of reactive enolate anions with S- and Se-(trifluoromethyl)chalcogen salts.Treatment of potassium or lithium enolates derived in situ from carbonyl compounds or enol trimethylsilyl ethers with S-(trifluoromethyl)dibenzothiophenium triflate (1) in the presence of 2-phenyl-1,3,2-benzodioxaborole (4) produced trifluoromethylated carbonyl compounds in high yields.In this manner, various α-CF3 ketones, γ-CF3-α,β-unsaturated ketones, and an α-CF3 ester were synthesized.Perfluorooctylation was similarly conducted using S-(perfluorooctyl)dibenzothiophenium triflate and 4.Thus, a balance of the reactivity of the reactants was essential for these electrophilic perfluoroalkylations.The deprotonation of 2-methylcyclohexanone with KN(SiMe3)2 followed by trifluoromethylation gave the 6-trifluoromethylated product regioselectively.In the trifluoromethylation of potassium enolate 16 of 4,4a,5,6,7,8-hexahydro-4a-methyl-2(3H)-naphthalenone, the use of bulky 2-mesitylphenanthro-1,3,2-dioxaborole (15) led to the diastereoselective formation of the thermodynamically less stable CF3-isomer 17β.For enantioselective trifluoromethylation, optically active (S)-4-phenyldinaphthodioxaborepin (19) and its 3,3'-diphenyl derivative 20 were synthesized.The trifluoromethylation of the potassium enolate of propiophenone with 1 in the presence of 20 afforded optically active α-CF3-propiophenone in 45percent ee yield.Thus, a new and versatile method for selective trifluoromethylation has been developed.