39199-22-9Relevant academic research and scientific papers
Synthesis of Vicinal Quaternary All-Carbon Centers via Acid-catalyzed Cycloisomerization of Neopentylic Epoxides
Schmid, Matthias,Sokol, Kevin R.,Wein, Lukas A.,Torres Venegas, Sofia,Meisenbichler, Christina,Wurst, Klaus,Podewitz, Maren,Magauer, Thomas
supporting information, p. 6526 - 6531 (2020/09/02)
We report our studies on the development of a catalytic cycloisomerization of 2,2-disubstituted neopentylic epoxides to produce highly substituted tetralins and chromanes. Termination of the sequence occurs via Friedel-Crafts-type alkylation of the remote (hetero)arene linker. The transformation is efficiently promoted by sulfuric acid and proceeds best in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) as the solvent. Variation of the substitution pattern provided detailed insights into the migration tendencies and revealed a competing disproportionation pathway of dihydronaphthalenes.
Sulfone Group as a Versatile and Removable Directing Group for Asymmetric Transfer Hydrogenation of Ketones
Clarkson, Guy J.,Vyas, Vijyesh K.,Wills, Martin
, p. 14265 - 14269 (2020/07/04)
The sulfone functional group has a strong capacity to direct the asymmetric transfer hydrogenation (ATH) of ketones in the presence of [(arene)Ru(TsDPEN)H] complexes by adopting a position distal to the η6-arene ring. This preference provides a
Biomimetic transfer hydrogenation of 2-alkoxy- and 2-aryloxyketones with iron-porphyrin catalysts
Enthaler, Stephan,Spilker, Bj?rn,Erre, Giulia,Junge, Kathrin,Tse, Man Kin,Beller, Matthias
, p. 3867 - 3876 (2008/09/20)
In situ generated iron porphyrins are applied as homogeneous catalysts in the transfer hydrogenation of α-substituted ketones. Using 2-propanol as hydrogen donor various protected 1,2-hydroxyketones are reduced to the corresponding mono-substituted 1,2-di
Synthesis, X-ray Structure and Reactions of (2-Oxoalkyl)triarylbismuthonium Salts
Matano, Yoshihiro,Azuma, Nagao,Suzuki, Hitomi
, p. 1739 - 1748 (2007/10/02)
Treatment of triarylbismuth difluorides 1 with silyl enol ethers 2 in the presence of boron trifluoride-diethyl ether or trimethylsilyl trifluoromethanesulfonate (triflate) gave (2-oxoalkyl)triarylbismuthonium tetrafluoroborates 3 and triflates 4 in good yields.A similar reaction of the difluorides 1 with hexamethyldisiloxane in the presence of the latter acid reagent led to the formation of oxybis(triarylbismuth) ditriflates 5.X-Ray crystallographic analyses of compounds 3a, 4a and 5a showed that the first two onium salts have a distorted tetrahedral geometry and the last, a μ-oxo type compound, has a distorted trigonal bipyramidal geometry around the bismuth centre.The stability of these bismuthonium salts may reasonably be attributed to the intramolecular coordinative interaction between the bismuth and oxygen atoms and also low nucleophilicity of the counter ions employed.The bismuthonium salt 3f readily underwent onium exchange with the phosphine 6 and the sulfide 9 to afford the corresponding phosphonium and sulfonium salts 7 and 10.The salts 3 and 4 also underwent coupling with a variety of nucleophiles such as the enolate 11, piperidine 13, the phenoxides 15, the thiolates 17, the sulfinate 19 and the halides 21 to afford the corresponding α-substituted ketones 12, 14, 16, 18, 20 and 22 in moderate to good yields, together with a good recovery of triphenylbismuthine 8.
Synthesis and reactivity of α-halomethyl ketimines
De Kimpe,De Cock,Stevens
, p. 2739 - 2760 (2007/10/02)
The synthesis of N-(1-halo-2-alkylidene)amines, i.e. α-halomethyl ketimines, is described for the first time, utilizing the TiCl4-induced condensation of α-halomethyl ketones with primary amines. The reactivity of these new α-halomethylketimines was studied with respect to nucleophiles such as iodide, cyanide, alcohols, alkoxides, amines and thiolates. α-Halomethyl ketimines are powerful ambident electrophiles which underwent a variety of reactions leading to functionalized imines and heterocycles.
