Eco-efficient, regioselective and rapid access to 4,5-disubstituted 1,2,3-thiadiazoles via [3 + 2] cycloaddition of α-enolicdithioesters with tosyl azide under solvent-free conditions
An efficient, eco-friendly, and highly convergent one-pot route to privileged thiazoloquinolinone derivatives has been developed via four-component cascade coupling (4CCC) of α-enolic dithioesters, cysteamine/2-aminothiophenols, aldehydes, and cyclic 1,3-diketones in recyclable [EMIM][EtSO4] ionicliquid at room temperature for the first time. The reaction proceeds via a N,S-acetal formation, Knoevenagel
Iron-Promoted Domino Annulation of α-Enolic Dithioesters with Ninhydrin under Solvent-Free Conditions: Chemoselective Direct Access to Indeno[1,2-<i>b</i>]thiophenes
An efficient, straightforward, and highly chemoselective strategy has been devised for the synthesis of a broad range of indeno[1,2-b]thiophenes through the annulation of α-enolic dithioesters with ninhydrin undersolvent-freeconditions. The advantages of this nucleophilic domino substitution/cyclization sequence are highlighted by the use of inexpensive and readily available FeCl3·6H2O as the catalyst
Site‐Specific S‐Allylation of α‐Enolic Dithioesters with Morita‐Baylis‐Hillman Acetates at Room Temperature: Precursor for Thiopyrans
作者:Sonam Soni、Suvajit Koley、Monish A. Ansari、Maya Shankar Singh
DOI:10.1002/adsc.201900580
日期:2019.9.3
An efficient one‐pot allylic alkylation of α‐enolic dithioesters (DTEs) with Morita‐Baylis‐Hillman (MBH) acetates has been devised in ethanol at room temperature. The reaction being site‐selective provided S‐allylated product exclusively with trace amount of C‐allylated one. Remarkably, some of the S‐allylated product undergoes [3,3]‐sigmatropic rearrangement to C‐allylated one under ethanol reflux
Metal‐ and Catalyst‐Free One‐Pot Cascade Coupling of α‐Enolic Dithioesters with in situ Generated 4‐Chloro‐3‐formylcoumarin: Access to Thioxothiopyrano[3,2‐
<i>c</i>
]chromen‐5(2
<i>H</i>
)‐ones
作者:Dhananjay Yadav、Monish A. Ansari、Mitilesh Kumar、Maya Shankar Singh
DOI:10.1002/adsc.201901180
日期:2020.2.6
for the synthesis of a specific class of 2‐thioxothiopyrano[3,2‐c] chromen‐5(2H)‐ones has been devised by the cross‐coupling of 4‐hydroxycoumarin and α‐enolic dithioesters under metal‐ and additive‐free conditions in open air. The reaction proceeds via in situ generation of 4‐chloro‐3‐formylcoumarin followed by consecutive Michael‐type addition/intramolecular cyclization/ eliminationcascade, enabling
通过4-羟基香豆素和α-羟基香豆素的交叉偶联,设计出了一种有效且可行的一锅法,用于合成特定类别的2-thioxothiopyrano [3,2 - c ] chromen -5(2 H)-ones。不含金属和添加剂的露天条件下的烯醇二硫酯。反应通过原位生成4-氯-3-甲酰基香豆素进行,然后连续进行Michael型加成/分子内环化/消除级联反应,从而通过连续形成C-C和C形成香豆素骨架上的噻喃-2-硫酮环。 CS键。值得注意的是,该功能策略的附加特性是良性条件,原子经济性和对广泛功能基团的承受能力。
Catalyst-free one-pot four-component domino reactions in water–PEG-400: highly efficient and convergent approach to thiazoloquinoline scaffolds
Catalyst-free one-pot sustainable synthesis of thiazoloquinoline and thiazolopyridine scaffolds is achievedviafour-component domino reactions in water–PEG.