Trichloromethyl ketones: asymmetric transfer hydrogenation and subsequent Jocic-type reactions with amines
作者:Michael S. Perryman、Matthew E. Harris、Jade L. Foster、Anushka Joshi、Guy J. Clarkson、David J. Fox
DOI:10.1039/c3cc46070c
日期:——
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.
A new and practical synthesis of vinyl dichlorides via a non-Wittig-type approach
作者:Zhe Wang、Silvio Campagna、Guoyou Xu、Michael E Pierce、Joseph M Fortunak、Pat N Confalone
DOI:10.1016/s0040-4039(00)00547-5
日期:2000.5
A practical approach for the conversion of aldehydes to vinyl dichlorides has been developed. These are three-step, one-pot reactions involving the formation of trichlorocarbinol by treatment of aldehydes with trichloroacetic acid and sodium trichloroacetate followed by in situ protection and elimination reactions to form the desired vinyl dichlorides in 85 to 95% yields.
A novel chain reaction induced by cathodic reduction was found in the reaction system consisting of carbon tetrachloride, chloroform, and electrophiles such as aldehydes or vinyl acetate. The current efficiency of addition of trichloromethylanion to electrophiles was extremely high. Synthesis of an analogue of ethyl chrysanthemate using this new reaction was also described.
1,1,1-Trichloroalkanols were readily obtained in good yields by reaction of trichloroacetic acid with aldehydes in hexamethylphosphoric triamide. 1,3-Dimethyl-2-imidazolidinone was found to be useful as an alternate solvent giving, however, lower yields.
Copper(I)/Ligand-Catalyzed 5-<i>endo</i> Radical Cyclization–Aromatization of 2,2,2-Trichloroethyl Vinyl Ethers: Synthesis of 2,3-Difunctionalized 4-Chlorofurans
作者:Ram N. Ram、Dharmendra Kumar Gupta、Vineet Kumar Soni
DOI:10.1021/acs.joc.5b02830
日期:2016.2.19
Copper(I)/ligand-catalyzed one pot synthesis of highly substituted 2,3-difunctionalized-4-chlorofurans has been reported. The reaction proceeds via a Cu(I)-catalyzed regioselective 5-endo-trig radical cyclization of 2,2,2-trichloroethyl vinyl ethers followed by the base-promoted dehydrochlorination. The success of the kinetically disfavored 5-endo cyclization was attributed to the formation of captodatively