Reduction of ethanethiol esters of α-amino acids to α-amino aldehydes by triethylsilane and catalytic palladium-on-carbon is described. α-Amino aldehydes with Boc, Cbz, or Fmoc protection could be obtained without racemization in high yield.
Formyloxyacetoxyphenylmethane as an <i>N</i>-Formylating Reagent for Amines, Amino Acids, and Peptides
作者:Robert S. L. Chapman、Ruth Lawrence、Jonathan M. J. Williams、Steven D. Bull
DOI:10.1021/acs.orglett.7b02382
日期:2017.9.15
Formyloxyacetoxyphenylmethane is a stable, water-tolerant, N-formylating reagent for primary and secondary amines that can be used under solvent-free conditions at room temperature to prepare a range of N-formamides, N-formylanilines, N-formyl-α-amino acids, N-formylpeptides, and an isocyanide.
Lead(IV) acetate mediated cleavage of β-hydroxy ethers: enantioselective synthesis of α-acetoxy carbonyl compounds
作者:Enrique Alvarez-Manzaneda、Rachid Chahboun、Esteban Alvarez、Ramón Alvarez-Manzaneda、Pedro E. Muñoz、Fermín Jimenez、Hanane Bouanou
DOI:10.1016/j.tet.2011.09.056
日期:2011.11
α-Acetoxy aldehydes or α-acetoxy ketones can be efficiently synthesized by treating 2,3-epoxy primary alcohols with lead tetraacetate. The reaction, which proceeds with complete regio- and stereoselectivity facilitates the enantioselective synthesis of α-acetoxy carbonyl compoundsfrom allyl alcohols, via Sharpless epoxidation. Cyclic β-hydroxy ethers, with an oxygenated five-, six- or seven-membered
Quantum chemical DFT calculations (B3LYP/6−31+G*) have been used to gain insight into the conformational and energy properties of the 1-aza- and 1-oxapentadienyl and -heptatrienyl cations 1, 2, 3, and 4. The calculated thermodynamic and kinetic data of the ring-closure reactions giving the cyclic products 5−14 are reported and discussed with respect to the experimental results. Experimentally, synthetic
Highly enantioselective reaction of lithiated N-Boc-thiazolidine: a new chiral formyl anion equivalent
作者:Libo Wang、Shuichi Nakamura、Takeshi Toru
DOI:10.1039/b408509d
日期:——
Reaction of lithiated N-Boc-thiazolidine with various aldehydes in the presence of (-)-sparteine afforded the products with up to 93% ee. The reaction was confirmed to proceed through a dynamic thermodynamicresolutionpathway. Each diastereomeric alcohol could be converted to the corresponding optically active 1,2-ethanediols.