Metal-Free Azidation of α-Hydroxy Esters and α-Hydroxy Ketones Using Azidotrimethylsilane
作者:Xiao-Ping Yin、Lei Zhu、Jian Zhou
DOI:10.1002/adsc.201701345
日期:2018.3.20
We herein report a commercially available perchloric acid catalyst capable of catalyzing the azidation of α‐hydroxy esters, α‐hydroxy ketones and taddols using azidotrimethylsilane in dichloromethane at room temperature. Various substituted tertiary alcohols are well tolerated in this reaction. Cα‐tetrasubstituted α‐amino acidderivatives were prepared by one‐pot sequential azidation and hydrogenation
Substituent Effects on the Solvolysis of 1,1-Diphenyl-2,2,2-trifluoroethyl Tosylates: Comparison between Symmetrically Disubstituted and Monosubstituted Systems
The solvolysis rates of 1-(substituted phenyl)-1-phenyl-2,2,2-trifluoroethyl and 1,1-bis(substituted phenyl)-2,2,2-trifluoroethyl tosylates or bromides were conductimetrically measured at 25.0 °C i...
A micro‐flow nucleophilic trifluoromethylation of carbonyl compounds using gaseous fluoroform was developed. This method also allows the first micro‐flow transformation of N‐sulfinylimines into trifluoromethyl amines with excellent diastereoselectivity. To demonstrate the synthetic utility of this micro‐flow synthesis, the formal micro‐flow synthesis of Efavirenz is described.
A chiral Rh–phosphite complex displaying high activity in the enantioselective Rh-catalyzed addition of arylboronic acids to carbonyl compounds: when and why atropos is better than tropos
作者:Varsha R. Jumde、Sarah Facchetti、Anna Iuliano
DOI:10.1016/j.tetasy.2010.11.009
日期:2010.12
The use of deoxycholic acid derived tropos and atropoisomeric phosphites as chiral ligands in the Rh-catalyzed enantioselective addition of arylboronic acids to arylaldehydes and 2,2,2-trifluoroacetophenone is presented. Screening of these phosphites showed the high activity of the Rh-complex obtained starting from one of the two atropoisomeric ligands, which afforded complete conversion of the carbonyl compounds in short reaction times under mild reaction conditions and with ee's of up to 84%. A study aimed at getting information about the different behavior of tropos and atropoisomeric ligands is also reported. (C) 2010 Elsevier Ltd. All rights reserved.