167113-72-6Relevant academic research and scientific papers
Unanticipated Silyl Transfer in Enantioselective α,β-Unsaturated Acyl Ammonium Catalysis Using Silyl Nitronates
Matviitsuk, Anastassia,Greenhalgh, Mark D.,Taylor, James E.,Nguyen, Xuan B.,Cordes, David B.,Slawin, Alexandra M. Z.,Lupton, David W.,Smith, Andrew D.
, p. 335 - 339 (2020)
The use of silyl nitronates is reported for the isothiourea-catalyzed synthesis of ?3-nitro-substituted silyl esters containing up to two contiguous stereocenters in good yields with excellent enantioselectivities (up to 93% yield and 99:1 er). The serendipitously discovered formation of silyl ester products in this reaction demonstrates a novel platform for catalyst turnover in α,β-unsaturated acyl ammonium catalysis.
Exploring the scope of tandem palladium and isothiourea relay catalysis for the synthesis of α-amino acid derivatives
Bitai, Jacqueline,Slawin, Alexandra M.Z.,Cordes, David B.,Smith, Andrew D.
supporting information, (2020/07/27)
The scope and limitations of a tandem N-allylation/[2,3]-rearrangement protocol are investigated through the incorporation of a variety of functional groups within an allylic phosphate precursor. This method uses readily accessible N,N-dimethylglycine aryl esters and functionalized allylic phosphates, forming quaternary ammonium salts in situ in the presence of a palladium catalyst. Subsequent enantioselective [2,3]-sigmatropic rearrangement, promoted by the chiral isothiourea tetramisole, generates α-amino acid derivatives with two contiguous stereocenters. The incorporation of electron-withdrawing ester and amide groups gave the best results, furnishing the desired products in moderate to good yields (29-70percent), with low diastereocontrol (typically 60:40 dr) but high enantioselectivity (up to 90:10 er). These results indicate that substrate-catalyst interactions in the proposed transition state are sensitive to the substitution pattern of the substrates.
