Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• Abstract In recent years, S-(alkyl)thianthrenium salts have become an important means of functionalizing alcohol compounds. However, additional transition metal catalysts and/or visible light are required. Herein, a direct thioetherification/amination reaction of thianthrenium salts is realized under metal

• -free conditions. This strategy exhibits good functional-group tolerance, operational simplicity, and an extensive range of compatible substrates. Keywords: amination; functionalization of alcohol; metal-free; S-(alkyl)thianthrenium salts; thioetherification; Introduction Sulfonium salts [1][2][3][4

• of a metal catalyst [46]. Results and Discussion With these considerations in mind, we investigated the possibility of the thioetherification between alkylthianthrenium salts and thiophenols. After extensive screening of the reaction parameters, the desired thioetherification product 3aa was obtained

Strategies in the synthesis of dibenzo[b,f]heteropines

• David I. H. Maier,
• Barend C. B. Bezuidenhoudt and
• Charlene Marais

Beilstein J. Org. Chem. 2023, 19, 700–718, doi:10.3762/bjoc.19.51

• categorised according to the major or final catalytic step employed to form the 7-membered heterocycle as several synthetic methods use multiple catalytic steps. 3.1 Buchwald–Hartwig amination, etherification and thioetherification The Buchwald–Hartwig reaction gives access to arylamines, -ethers and

• ]oxepine 54 and -azepine 55 derivatives via (i) Heck reaction and (ii) Buchwald–Hartwig-type etherification or amination. Double Buchwald–Hartwig amination and thioetherification in the synthesis of tricyclic azepines 60 and thiepines 52. Double Buchwald–Hartwig amination towards substituted

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• (129) followed by the reduction [61] of the aldehyde gave the corresponding benzyl alcohol 131 in 76% yield. Deacetylation in the presence of hydrazine [62] followed by intramolecular thioetherification led to the macrocycle 133. Finally, the oxidation of the obtained thioether to the corresponding

Recent synthesis of thietanes

• Jiaxi Xu

Beilstein J. Org. Chem. 2020, 16, 1357–1410, doi:10.3762/bjoc.16.116

• of sulfur-containing acyclic and heterocyclic compounds [10][11]. Several synthetic methods for thietanes have been developed and reviewed [12][13][14]. One traditional route is the intermolecular double substitution (cyclic thioetherification) of 1,3-dihaloalkanes, sulfonates of 3-haloalkan-1-ols

• ) hydrogen chloride salt after the acidic deprotection [37] (Scheme 5). During recent decades, the cyclic thioetherification strategy was widely applied in the synthesis of thietane-based square sugurs (thietanoses), and sulfur-containing glycomimetics of furanoses and pyranoses [38]. The first thietanose

• ). Following similar protocols, (S,S)-2,3-bis(benzoyloxymethyl)thietane (34) was synthesized from diethyl L-tartrate (32), which was further converted into thietanocin A (35), a sulfur analogue of oxetanocin A [39] (Scheme 7). The double displacement cyclic thioetherification strategy was also utilized for the

β-Hydroxy sulfides and their syntheses

• Mokgethwa B. Marakalala,
• Edwin M. Mmutlane and
• Henok H. Kinfe

Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143

• [73] (Scheme 39). The reaction was found to be useful in both intra- and intermolecular thioetherification to yield the regioisomers in ratios that were dependent on the steric bulk of the substituents on the alkene (Scheme 39). The reaction was proposed to proceed via initial transfer of the thiolate

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

• Johannes Schörgenhumer,
• Maximilian Tiffner and
• Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

• ; thioetherification; Introduction In the 1960s and 1970s, the groups of Makosza, Starks, and Brändström pioneered the field of “phase transfer catalysis” by showing the beneficial effect of tetraalkyl-ammonium or -phosphonium salts to facilitate reactions between components that are present in two immiscible phases