One-pot sequential synthesis of tetrasubstituted thiophenes via sulfur ylide-like intermediates

• Jun Ki Kim,
• Hwan Jung Lim,
• Kyung Chae Jeong and
• Seong Jun Park

Beilstein J. Org. Chem. 2018, 14, 243–252, doi:10.3762/bjoc.14.16

• those of others. Keywords: 5-(heterocyclic)thiophenes; one-pot sequential synthesis; sulfur ylide; tetrasubstituted thiophene; Introduction Since the discovery of stable sulfonium ylides 1 in 1930 [1] and the pioneering work of several research groups during the 1960s (2 and 3) [2][3][4][5][6][7][8][9

• -pot sequential synthesis of the trisubstituted 5-(pyridine-2-yl)thiophenes 8a. Substrate: amalonitrile; b5,5-dimethylcyclohexane-1,3-dione. The substitution reaction with MeOH. Examination of N,S-acetals substituted with a heterocycle (7aa–k) or an arene (7l–p). 1H NMR studies of Meldrum’s acid-based

• ], 4 [11][12], 5 [33][34], 6 [35][36][37][38]. Metal-free synthesis of thiophene-based heterocycles (A) [54][55], (B) [56]. X-ray crystal structures of 8ad and 8an [68]. The proposed structure of sulfur ylide-like intermediates; resonance contributors (mesomeric structures) [69][70][71][72][78]. One

Clean and fast cross-coupling of aryl halides in one-pot

• Valerica Pandarus,
• Geneviève Gingras,
• François Béland,
• Rosaria Ciriminna and
• Mario Pagliaro

Beilstein J. Org. Chem. 2014, 10, 897–901, doi:10.3762/bjoc.10.87

• intermediate boronic acid pinacol ester. The overall process is described by Scheme 2. The SiliaCat DPP-Pd catalyst mediates the borylation and the subsequent Suzuki–Miyaura reaction in an elegant one-pot sequential synthesis. Hence, an aryl bromide is first converted into the boronic acid pinacol ester (step

One-pot sequential synthesis of isocyanates and urea derivatives via a microwave-assisted Staudinger–aza-Wittig reaction

• Diego Carnaroglio,
• Katia Martina,
• Giovanni Palmisano,
• Andrea Penoni,
• Claudia Domini and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2013, 9, 2378–2386, doi:10.3762/bjoc.9.274

• a one-pot, sequential synthesis of urea derivatives from alkyl bromides. With the aim to verify the feasibility of the method under conventional heating, the protocol was tested in a Parr reactor (90 mL) for an easier scale-up. Results and Discussion The Staudinger–aza-Wittig reaction is extremely