909906-70-3Relevant academic research and scientific papers
N-Urethane protection of amines and amino acids in an ionic liquid
Di Gioia,Gagliardi,Leggio,Leotta,Romio,Liguori
, p. 63407 - 63420 (2015)
An efficient, solvent-free protocol for the N-fluorenylmethoxycarbonylation and N-benzyloxycarbonylation of amines is described. The reaction of aliphatic and aromatic amines with FmocOSu and Cbz-Osu in [Bmim][BF4] at room temperature afforded the corresponding N-urethane derivatives in excellent yields and do not require any further purification. The method has been extended to the N-Fmoc and N-Cbz protection of amino acids. Absence of bases, very short reaction times, high yields, selectivity and ease of product separation are some advantages of this protocol.
Carbamate Synthesis Using a Shelf-Stable and Renewable C1 Reactant
Dobi, Zoltán,Reddy, B. Narendraprasad,Renders, Evelien,Van Raemdonck, Laurent,Mensch, Carl,De Smet, Gilles,Chen, Chen,Bheeter, Charles,Sergeyev, Sergey,Herrebout, Wouter A.,Maes, Bert U. W.
, p. 3103 - 3114 (2019/06/24)
4-Propylcatechol carbonate is a shelf-stable, renewable C1 reactant. It is easily prepared from renewable 4-propylcatechol (derived from wood) and dimethyl carbonate (derived from CO2) using a reactive distillation system. In this work, the 4-propylcatechol carbonate is used for the two-step synthesis of carbamates under mild reaction conditions. In the first step, 4-propylcatechol carbonate is treated with an alcohol at 50–80 °C in the presence of a Lewis acid catalyst, such as Zn(OAc)2?2 H2O. With liquid alcohols, no solvent is used and with solid alcohols 2-methyltetrahydrofuran is used as solvent. In the second step, the alkyl 2-hydroxy-propylphenyl carbonate intermediates obtained react with amines at room temperature in 2-methyltetrahydrofuran, forming the target carbamates and the byproduct 4-propylcatechol, which can be recycled into a carbonate reactant.
Anti-Markovnikov Radical Hydro- and Deuteroamidation of Unactivated Alkenes
Jiang, Heng,Studer, Armido
, p. 7105 - 7109 (2019/05/15)
Radical anti-Markovnikov hydro- and deuteroamidation of unactivated alkenes was achieved by merging photoredox and thiol catalysis. Reactions proceed by addition of the electrophilic CbzHN-radical (Cbz=carbobenzyloxy), readily generated by single-electron-transfer (SET) oxidation of an α-Cbz-amino-oxy acid to an alkene. The adduct radical is reduced by thiophenol added as an organic polarity reversal cocatalyst, which mediates the H transfer from H2O to the alkyl radical intermediate. Accordingly, deuteroamidation of alkenes was realized with excellent D incorporation by using D2O as the stoichiometric formal radical-reducing reagent. The reaction features low redox catalyst loading, excellent anti-Markovnikov selectivity, and the use of a large alkene excess is not required. Diverse Cbz-protected primary amines, including β-deuterated amines, can be obtained by applying this method.
Stereoselective direct reductive amination of ketones with electron-deficient amines using Re2O7/NaPF6 catalyst
Das, Braja Gopal,Ghorai, Prasanta
supporting information, p. 4379 - 4382 (2013/08/23)
The first example of direct reductive amination (DRA) of ketones with electron-deficient amines (EDA) such as Cbz-, Boc-, EtOCO-, Fmoc-, Bz-, ArSO2-, etc. protected amines have been achieved using catalytic Re2O7/NaPF6. Excellent chemoselectivities as well as diastereoselectivity (for 2-alkyl cyclohexanones) were obtained. The Royal Society of Chemistry 2013.
