1555-80-2Relevant articles and documents
Stereoselective Lewis base catalyzed formal 1,3-dipolar cycloaddition of azomethine imines with mixed anhydrides
Hesping, Lena,Biswas, Anup,Daniliuc, Constantin G.,Mück-Lichtenfeld, Christian,Studer, Armido
, p. 1252 - 1257 (2015)
Stereoselective synthesis of pyrazolidinones via dipolar cycloaddition of azomethine imines with active esters under Lewis base catalysis is presented. The active esters are readily generated in situ from the corresponding acids. Products, which are obtai
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Davidson,Newman
, p. 1515 (1952)
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Formamide catalyzed activation of carboxylic acids-versatile and cost-efficient amidation and esterification
Huy, Peter H.,Mbouhom, Christelle
, p. 7399 - 7406 (2019/08/20)
A novel, broadly applicable method for amide C-N and ester C-O bond formation is presented based on formylpyrrolidine (FPyr) as a Lewis base catalyst. Herein, trichlorotriazine (TCT), which is the most cost-efficient reagent for OH-group activation, was employed in amounts of ≤40 mol% with respect to the starting material (100 mol%). The new approach is distinguished by excellent cost-efficiency, waste-balance (E-factor down to 3) and scalability (up to >80 g). Moreover, high levels of functional group compatibility, which includes acid-labile acetals and silyl ethers, are demonstrated and even peptide C-N bonds can be formed. In comparison to reported amidation procedures using TCT, yields are considerably improved (for instance from 26 to 91%) and esterification is facilitated for the first time in synthetically useful yields. These significant enhancements are rationalized by activation by means of acid chlorides instead of less electrophilic acid anhydride intermediates.
Protected pyrimidine nucleosides for cell-specific metabolic labeling of RNA
Beasley, Samantha,Nguyen, Kim,Fazio, Michael,Spitale, Robert C.
supporting information, p. 3912 - 3915 (2018/09/27)
RNA molecules can perform a myriad of functions, from the regulation of gene expression to providing the genetic blueprint for protein synthesis. Characterizing RNA expression dynamics, in a cell-specific manner, still remains a great challenge in biology. Herein we present a new set of protected alkynyl nucleosides for cell-specific metabolic labeling of RNA. We anticipate these analogs will find wide spread utility toward the goal of understanding RNA expression in complex cellular and tissue environments, even within living animals.
