88001-42-7Relevant articles and documents
Expedient preparation of nazlinine and a small library of indole alkaloids using flow electrochemistry as an enabling technology
Kabeshov, Mikhail A.,Musio, Biagia,Murray, Philip R.D.,Browne, Duncan L.,Ley, Steven V.
, p. 4618 - 4621 (2014)
An expedient synthesis of the indole alkaloid nazlinine is reported. Judicious choice of flow electrochemistry as an enabling technology has permitted the rapid generation of a small library of unnatural relatives of this biologically active molecule. Furthermore, by conducting the key electrochemical Shono oxidation in a flow cell, the loading of electrolyte can be significantly reduced to 20 mol % while maintaining a stable, broadly applicable process.
Enzymatic and chromatographic resolution procedures applied to the synthesis of the phosphoproline enantiomers
Arizpe, Alicia,Rodríguez-Mata, María,Sayago, Francisco J.,Pueyo, María J.,Gotor, Vicente,Jiménez, Ana I.,Gotor-Fernández, Vicente,Cativiela, Carlos
, p. 1469 - 1477 (2015/12/09)
The preparation of enantiomerically pure pyrrolidine-2-phosphonic acid (phosphoproline, ProP) has been addressed through the synthesis of suitable racemates and subsequent resolution by independent enzyme-catalyzed and chiral HPLC methods. First, racemic phosphoproline derivatives bearing the necessary protecting groups have been synthesized in excellent global yields starting from inexpensive materials. Preparative HPLC resolution of the N-Cbz-protected aminophosphonate on a cellulose-based column allowed the isolation of enantiomerically pure enantiomers on a gram scale. Enzyme-catalyzed alkoxycarbonylation of the aminophosphonate was studied using different lipases, solvents, and carbonates. Candida antarctica lipase type A (CAL-A) provided the highest enantioselectivity when combined with benzyl 3-methoxyphenyl carbonate.
α-amidoalkylating agents from N-acyl-α-amino acids: 1-(N-acylamino)alkyltriphenylphosphonium salts
Mazurkiewicz, Roman,Adamek, Jakub,Pazdzierniok-Holewa, Agnieszka,Zielinska, Katarzyna,Simka, Wojciech,Gajos, Anna,Szymura, Karol
experimental part, p. 1952 - 1960 (2012/04/17)
N-Acyl-α-amino acids were efficiently transformed in a two-step procedure into 1-N-(acylamino)alkyltriphenylphosphonium salts, new powerful α-amidoalkylating agents. The effect of the α-amino acid structure, the base used [MeONa or a silica gel-supported piperidine (SiO 2-Pip)], and the main electrolysis parameters (current density, charge consumption) on the yield and selectivity of the electrochemical decarboxylative α-methoxylation of N-acyl-α-amino acids (Hofer-Moest reaction) was investigated. For most proteinogenic and all studied unproteinogenic α-amino acids, very good results were obtained using a substoichiometric amount of SiO2-Pip as the base. Only in the cases of N-acylated cysteine, methionine, and tryptophan, attempts to carry out the Hofer-Moest reaction in the applied conditions failed, probably because of the susceptibility of these α-amino acids to an electrochemical oxidation on the side chain. The methoxy group of N-(1-methoxyalkyl)amides was effectively displaced with the triphenylphosphonium group by dissolving an equimolar amount of N-(1-methoxyalkyl)amide and triphenylphosphonium tetrafluoroborate in CH 2Cl2 at room temperature for 30 min, followed by the precipitation of 1-N-(acylamino)alkyltriphenylphosphonium salt with Et 2O.
