200501-07-1Relevant articles and documents
N-heterocyclic carbene-catalyzed fluorinated silyl-Reformatsky reaction of aldehydes with difluoro (trimethylsilyl) acetate
Wang, Ying,Xing, Fen,Gu, Cheng-Zhi,Li, Wen-Juan,He, Lin,Dai, Bin,Du, Guang-Fen
, p. 4501 - 4507 (2017/07/03)
N-Heterocyclic carbenes (NHCs) have been employed as highly efficient organocatalysts for fluorinated silyl-Reformatsky reaction of carbonyl compounds. In the presence of 5–10 mol % NHC A, various aldehydes and 2,2,2–trifluoroacetophenone reacted with difluoro (trimethylsilyl) acetate to produce β–hydroxy gem–difluoro esters in 20–96% yields.
Ligand-controlled regiodivergent palladium-catalyzed decarboxylative allylation reaction to access α,α-difluoroketones
Yang, Ming-Hsiu,Orsi, Douglas L.,Altman, Ryan A.
supporting information, p. 2361 - 2365 (2015/03/04)
α,α-Difluoroketones possess unique physicochemical properties that are useful for developing therapeutics and probes for chemical biology. To access the α-allyl-α,α-difluoroketone substructure, complementary palladium-catalyzed decarboxylative allylation reactions were developed to provide linear and branched α-allyl-α,α-difluoroketones. For these orthogonal processes, the fluorination pattern of the substrate enabled the ligands to dictate the regioselectivity of the transformations.
A mild, efficient synthesis of gem -difluorodihydrouracils
Olimpieri, Francesca,Fustero, Santos,Volonterio, Alessandro,Zanda, Matteo
scheme or table, p. 651 - 660 (2010/04/30)
Carbodiimides react effectively with -aryl/alkyl - hydroxy-,- difluorocarboxylic acids to afford a vast array of fully substituted gem-difluorodihydrouracils through a two step reaction sequence. In the first step, condensation between the two reactants leads in most cases to the formation of a mixture of the desired dihydrouracils and N-acylurea co-products. However, the latter could be easily recovered and efficiently converted into the target compounds. The sequence works well in very mild conditions (CHl 20C) and the reaction resulted to be completely regioselective when asymmetric carbodiimides were used. When the N-acylurea derivatives are not sufficiently stable for isolation, the process could be done in a one-pot fashion leading to the direct formation of the desired dihydrouracils, although in lower yields. Georg Thieme Verlag Stuttgart · New York.
Kinetic resolution of 2,2-difluoro-3-hydroxy-3-aryl-propionates catalyzed by organocatalyst (R)-benzotetramisole
Zhou, Hui,Xu, Qing,Chen, Peiran
, p. 6494 - 6499 (2008/09/21)
Kinetic resolution of a series of ethyl 2,2-difluoro-3-hydroxy-3-aryl-propionates catalyzed by (R)-benzotetramisole has been performed. It was found that when the aryl group was phenyl or phenyl substituted with electron-donating group (such as -Me, -OMe,
Rhodium-catalyzed Reformatsky-type reaction of ethyl bromodifluoroacetate
Sato, Kazuyuki,Tarui, Atsushi,Kita, Tetsuya,Ishida, Yoshitaka,Tamura, Hanae,Omote, Masaaki,Ando, Akira,Kumadaki, Itsumaro
, p. 5735 - 5737 (2007/10/03)
Treatment of a variety of carbonyl compounds with ethyl bromodifluoroacetate and Et2Zn in the presence of RhCl(PPh 3)3 in CH3CN afforded Reformatsky-type products in good to excellent yields in a mild reaction c
Practical and efficient synthesis of alkyl, alkenyl and aryl-alkyl α,α-difluoro esters as precursors of potential inhibitors of the pheromone catabolism in insects
Jimenez,Bosch,Guerrero
, p. 1917 - 1924 (2007/10/03)
An efficient method for the synthesis of long chain alkyl, alkenyl and aryl-alkyl α,α-difluoro esters through reductive cleavage of the corresponding S-methyl dithiocarbonates with diphenylphosphine oxide and di-tert-butyl peroxide as initiator is reported. The α,α-difluoro esters 4a-j have been obtained for the first time and in good overall yields. A limitation of the method is the presence of radical-sensitive functions, such as disubstituted double or triple bonds, in the substrate since the concomitant addition of the phosphonyl radical to the unsaturated carbons may induce isomerization of the double bond or polymerization. If stereomerically pure alkenyl α,α-difluoro esters are required, it is suggested to run the reductive cleavage on the S-methyl dithiocarbonate of the acetylenic precursor followed by stereoselective hydrogenation to the alkene.
Synthesis and structure-activity relationships of novel 2',2'-difluoro analogues of docetaxel
Uoto, Kouichi,Ohsuki, Satoru,Takenoshita, Haruhiro,Ishiyama, Takashi,Iimura, Shin,Hirota, Yasuhide,Mitsui, Ikuo,Terasawa, Hirofumi,Soga, Tsunehiko
, p. 1793 - 1804 (2007/10/03)
To investigate the role of the 2'-hydroxy group at the C-13 side chain of docetaxel in the antitumor activity, we prepared several 2',2'-difluoro derivatives of docetaxel and evaluated their cytotoxicity against mouse leukemia and human tumor cell lines a
