A One-Pot Assembly of Fully Substituted Alkyl 5-Aminothiophene-2-carboxylates from Allenes, Isothiocyanates, and Alkyl 2-Bromoacetates
作者:Nina A. Nedolya、Ol’ga A. Tarasova、Alexander I. Albanov、Boris A. Trofimov
DOI:10.1021/acs.joc.7b01217
日期:2017.7.21
A novel simple approach to highlyfunctionalized multisubstituted thiophenes such as alkyl 4-alkoxy-5-amino-3-methylthiophene-2-carboxylates through the one-pot sequential reaction of α-lithiated alkoxyallenes with isothiocyanates and alkyl 2-bromoacetates has been discovered. The process proceeds quickly (30–45 min) via in situ formation and intramolecular cyclization of alkyl 2-[(2-alkoxybuta-2,
Synthesis of 2-[(5-Amino-1H-pyrrol-2-yl)sulfanyl]acetic Acid Esters: One-Pot Assembly from Propargyl Amines, Isothiocyanates, and Alkyl 2-Bromoacetates
作者:Olga A. Tarasova、Nina A. Nedolya、Alexander I. Albanov、Boris A. Trofimov
DOI:10.1055/s-0037-1611883
日期:2019.10
Abstract 2-[(5-Amino-1H-pyrrol-2-yl)sulfanyl]acetic acidesters have been synthesized in up to 77% yield by the one-pot reaction of lithiated propargylamines with isothiocyanates followed by sequential treatment with t-BuOK–DMSO and alkyl 2-bromoacetates. The process occurs through the initial formation of the thiophene core, followed by its recyclization into the pyrrole nucleus at a higher temperature
Allenic Compounds and Isothiocyanates as Key Building Units in the Synthesis of Heterocycles
作者:Lambert Brandsma、Nina A. Nedolya
DOI:10.1055/s-2004-816005
日期:——
attack of the thiolate moiety on the allenic system and subsequent addition of methyl iodide or protonation. 1 Introduction 2 Generation of Allenic Lithium Compounds 3 Formation of 2,3-Dihydropyridines or Mixtures of 2,3-Dihydropyridines and Pyrroles 4 Directed Synthesis of Pyrroles 5 Synthesis of Quinolines 6 Synthesis of Cyclobutanopyrrolines 7 Synthesis of Thiophene and Dihydrothiophene Derivatives
Expeditious Scalable Catalyst-Free One-Pot Synthesis of 4-Alkoxy-5-amino-3-methylthiophene-2-carbonitriles via Sequential Reactions of Lithiated Alkoxyallenes with Isothiocyanates and 2-Bromoacetonitrile
Abstract A synthetically simple and convenient approach to tetrasubstituted thiophenes with rare combination of the alkoxy, amino, and cyano groups has been developed. The assembly of polyfunctionalized thiophene ring is implemented in one preparative step by sequential addition of isothiocyanate and 2-bromoacetonitrile to the lithiated (with n-BuLi) alkoxyallene. The reaction proceeds through in situ
Mass spectra of new heterocycles: XII. Main fragmentation pathways of the molecular ions of 5-methylsulfanyl-1-vinyl-1H-pyrrol-2-amines under electron impact and chemical ionization
作者:L. V. Klyba、N. A. Nedolya、O. A. Tarasova、E. R. Sanzheeva
DOI:10.1134/s1070428014010072
日期:2014.1
Fragmentation patterns of 5-methylsulfanyl-1-vinyl-1H-pyrrol-2-amines under electronimpact (70 eV) and chemicalionization (methane as reactant gas) were studied for the first time. The electronimpactmassspectra of all the examined compounds contained a strong peak of molecular ion which decomposed along four pathways. Two pathways involved cleavage of the C-S bonds with elimination of methyl (major)
首次研究了在电子轰击(70 eV)和化学电离作用下(甲烷作为反应气体)5-甲基硫烷基-1-乙烯基-1 H-吡咯-2-胺的裂解模式。所有检查的化合物的电子冲击质谱图均包含一个强烈的分子离子峰,该峰沿四个路径分解。两条途径涉及CS键的裂解,消除了甲基(主要)和MeS自由基(次要),另外两个途径是吡咯环的分解。化学电离质谱显示出强分子[ M + H] +和奇电子[ M + H-SMe] +离子峰。N,N-二甲基-5-甲基硫烷基-4-苯基-1-乙烯基-1在以甲烷为反应气体的化学电离下,H-吡咯-2-胺的特征在于分解为[ M -C 4 H 9 N] +作为唯一的碎片离子。