Automated Synthesis and Purification of Amides: Exploitation of Automated Solid Phase Extraction in Organic Synthesis
作者:R. Michael Lawrence、Scott A. Biller、Olga M. Fryszman、Michael A. Poss
DOI:10.1055/s-1997-1232
日期:1997.5
Automated parallel synthesis of small organic molecules, either as single entities or as mixtures, offers the potential for the rapid optimization of physical and biological properties of a molecule. Currently, emphasis has been placed on solid phase synthesis technology to accomplish the rapid preparation of large numbers of molecules. Automated solution phase synthesis is an alternative approach which has the advantages of having shorter development times and being more amenable to scaleup. Utilizing commercially available liquid handlers for reaction setup and exploiting automated solid phase extraction for product purification, a procedure has been developed to prepare and purify up to 100 amide analogs, simultaneously. Both carbodiimide mediated couplings and p-nitrophenyl ester displacements have been carried out using this procedure. Product amides having overall neutral or basic character have been prepared in good yield and with good to excellent purities.
A Lewis-acid-catalyzed method for the substrate-directed formation of peptide bonds has been developed, and this powerful approach is utilized for the new "remote" activation of carboxyl groups under solvent-free conditions. The presented method has the following advantages: 1) the high-yielding peptidesynthesis uses a tantalum catalyst for any amino acids; 2) the reaction proceeds without any racemization;
Two-Component Redox Organocatalyst for Peptide Bond Formation
作者:Handoko、Nihar R. Panigrahi、Paramjit S. Arora
DOI:10.1021/jacs.1c12798
日期:2022.3.2
Peptides are fundamental therapeutic modalities whose sequence-specific synthesis can be automated. Yet, modern peptidesynthesis remains atom uneconomical and requires an excess of coupling agents and protected aminoacids for efficient amide bond formation. We recently described the rational design of an organocatalyst that can operate on Fmoc aminoacids─the standard monomers in automated peptide
A simple NaOMe catalyst provides superior accessibility to a wide variety of functionalized amides including peptides through direct amination of esters in an atom-economical and environmentally benign way.
Biomimetic Peptide Catalytic Bond‐Forming Utilizing a Mild Brønsted Acid
作者:Erika Nakashima、Hisashi Yamamoto
DOI:10.1002/chem.202103989
日期:2022.6.21
flow synthesis at room temperature using organic solvents with boiling points below 100 °C. The method applies the tert-butoxycarbonyl amino methoxy group, forming the desired dipeptide without solvent at mild temperatures. Furthermore, the conversion of the carboxylic acid leaving the group to phenyl ester promotes peptide bond formation, and the reaction were applied to di, tri, and tetrapeptide bond