10075-06-6Relevant academic research and scientific papers
Catalytic ketone olefination with methyltrioxorhenium
Pedro, Filipe M.,Hirner, Sebastian,Kühn, Fritz E.
, p. 7777 - 7779 (2005)
Methyltrioxorhenium (MTO) catalyses the olefination of ketones with ethyl diazoacetate in the presence of triphenylphosphane. Unactivated ketones require the addition of 0.5 equiv of benzoic acid to achieve good yields, while trifluoromethyl ketones require no co-catalyst. The optimised system allows the olefination of aromatic, aliphatic, unsaturated, cyclic and trifluoromethyl ketones.
HP(O)Ph2/H2O-promoted hydrodefluorination of trifluoromethyl alkenes
Chen, Jia-Wei,Chen, Yu-Lan,Chu, Xue-Qiang,Ma, Mengtao,Shen, Zhi-Liang,Sun, Li-Wen,Ying, Xuan
supporting information, p. 2777 - 2782 (2022/04/12)
An efficient transition-metal-free hydrodefluorination reaction of trifluoromethyl alkenes for accessing gem-difluoroalkenes is developed. It was surprising to find that the phosphoryl anion is able to mediate the defluorination. The successful realizatio
Highly Selective and Catalytic Generation of Acyclic Quaternary Carbon Stereocenters via Functionalization of 1,3-Dienes with CO2
Chen, Xiao-Wang,Zhu, Lei,Gui, Yong-Yuan,Jing, Ke,Jiang, Yuan-Xu,Bo, Zhi-Yu,Lan, Yu,Li, Jing,Yu, Da-Gang
, p. 18825 - 18835 (2019/11/28)
The catalytic asymmetric functionalization of readily available 1,3-dienes is highly important, but current examples are mostly limited to the construction of tertiary chiral centers. The asymmetric generation of acyclic products containing all-carbon quaternary stereocenters from substituted 1,3-dienes represents a more challenging, but highly desirable, synthetic process for which there are very few examples. Herein, we report the highly selective copper-catalyzed generation of chiral all-carbon acyclic quaternary stereocenters via functionalization of 1,3-dienes with CO2. A variety of readily available 1,1-disubstituted 1,3-dienes, as well as a 1,3,5-triene, undergo reductive hydroxymethylation with high chemo-, regio-, E/Z-, and enantioselectivities. The reported method features good functional group tolerance, is readily scaled up to at least 5 mmol of starting diene, and generates chiral products that are useful building blocks for further derivatization. Systemic mechanistic investigations using density functional theory calculations were performed and provided the first theoretical investigation for an asymmetric transformation involving CO2. These computational results indicate that the 1,2-hydrocupration of 1,3-diene proceeds with high π-facial selectivity to generate an (S)-allylcopper intermediate, which further induces the chirality of the quaternary carbon center in the final product. The 1,4-addition of an internal allylcopper complex, which differs from previous reports involving terminal allylmetallic intermediates, to CO2 kinetically determines the E/Z- and regioselectivity. The rapid reduction of a copper carboxylate intermediate to the corresponding silyl-ether in the presence of Me(MeO)2SiH provides the exergonic impetus and leads to chemoselective hydroxymethylation rather than carboxylation. These results provide new insights for guiding further development of asymmetric C-C bond formations with CO2
Convenient stereoselective synthesis of β-perfluoroalkyl α,β-unsaturated esters via H?rner-Wadsworth-Emmons reactions
Yamazaki, Takashi,Mano, Noriko,Hikage, Reo,Kaneko, Tsutomu,Kawasaki-Takasuka, Tomoko,Yamada, Shigeyuki
, p. 8059 - 8066 (2015/12/30)
Condensation of H?rner-Wadsworth-Emmons reagents 3 and ketones 2 with a perfluoroalkyl (Rf) moiety prepared in situ was proved to be significantly efficient and powerful methods for the construction of a wide variety of α,β-unsaturated esters with Rf and R1 groups both at the β-position due to convenient avoidance of usually tedious as well as troublesome isolation steps of these ketones 2.
Synthesis of cytotoxic fluorinated quassinoids
Ohno, Nobuhiro,Fukamiya, Narihiko,Okano, Masayoshi,Tagahara, Kiyoshi,Lee, Kuo-Hsiung
, p. 1489 - 1495 (2007/10/03)
The C-15 senecioyl side chain of brusatol was interchanged with fluorinated acyl groups, and the C-3 hydroxy group of bruceolide was esterified with fluorinated acyl chlorides. These fluorinated quassinoids 11, 12, 13, and 17 showed significant cytotoxic activity against eight human cancer cell lines including small and non-small cell lung, colon, CNS, ovarian and renal cancers, leukemia, and melanoma with 17 being about 100 times more potent than 11, 12, and 13. The activity of 17 was similar to that of bruceantin (1) in this in vitro cell line panel.
Synthesis and Thermolysis of Highly Halogenated Δ1-Pyrazolines
Huff, Roger K.,Savins, Eric G.
, p. 742 - 743 (2007/10/02)
The pyrolysis of highly halogenated Δ1-pyrazolines gives, in addition to cyclopropanes, rearranged olefins.
