780760-99-8Relevant academic research and scientific papers
A new process for the generation of 1,3,2-oxazaborolidines, catalysts for enantioselective synthesis
Corey,Link
, p. 4141 - 4144 (1992)
A simple and easily reproducible procedure for the formation of 1,3,2-oxazaborolidines from β-amino alcohols and bis(trifluoroethyl) alkylboronates, is reported along with a new synthesis of the latter.
Trichloromethyl ketones: Asymmetric transfer hydrogenation and subsequent Jocic-type reactions with amines
Perryman, Michael S.,Harris, Matthew E.,Foster, Jade L.,Joshi, Anushka,Clarkson, Guy J.,Fox, David J.
supporting information, p. 10022 - 10024 (2013/10/22)
Amino-amides are important pharmaceutical building-blocks. The enantioselective reduction of trichloromethyl ketones using ruthenium transfer hydrogenation catalysts is reported. The products react in a range of Jocic-type reactions to give enantiomerically enriched amino-amides.
Meerwein-Ponndorf-Verley alkynylation of aldehydes: Essential modification of aluminium alkoxides for rate acceleration and asymmetric synthesis
Ooi, Takashi,Miura, Tomoya,Ohmatsu, Kohsuke,Saito, Akira,Maruoka, Keiji
, p. 3312 - 3319 (2007/10/03)
A novel carbonyl alkynylation has been accomplished based on utilization of the Meerwein-Ponndorf-Verley (MPV) reaction system. The success of the MPV alkynylation crucially depends on the discovery of the remarkable ligand acceleration effect of 2,2′-biphenol. For example, the alkynylation of chloral (2c) with the aluminium alkoxide 6 (R = Ph), prepared in situ from Me3Al, 2,2′-biphenol and 2-methyl-4-phenyl-3-butyn-2-ol (1a) as an alkynyl source, proceeded smoothly in CH2Cl2 at room temperature to give the desired propargyl alcohol 3ca in almost quantitative yield after 5 h stirring. The characteristic feature of this new transformation involving no metal alkynides can be visualized by the fact that the alkynyl group bearing keto carbonyl was transferred successfully to aldehyde carbonyl without any side reactions on keto carbonyl. Although the use of (S)-1,1′-bi-2-naphthol and its simple analogues was found to be unsuitable for inducing asymmetry in this reaction, design of new chiral biphenols bearing a certain flexibility of the biphenyl axis led to satisfactory results in terms of enantioselectivity as well as reactivity.
The first highly enantioselective alkynylation of chloral: A practical and efficient pathway to chiral trichloromethyl propargyl alcohols
Jiang, Biao,Si, Yu-Gui
, p. 669 - 674 (2007/10/03)
A new, inexpensive chiral amino alcohol-based ligand, (1S,2S)-2-N,N- dimethylamino-1-(4-nitrophenyl)-3-(tert-butyloxy)propan-1-ol, was developed for the asymmetric alkynylation of chloral in high yield with up to 98% ee. The resulting chiral adduct (S)-1-trichloromethyl-3-phenyl-2-propyn-1-ol was hydrogenated over 10% Pd/C to give the useful intermediate chiral trichloromethyl carbinol in quantitative yield, which was efficiently transformed into the pharmaceutically important building blocks 2-hydroxy-4-phenylbutanoate and homophenylalanine in high yield with excellent enantiomeric excess.
