Syntheses of 4H-Thiopyran-4-one 1,1-Dioxides as Precursors to Sulfone-Containing Analogs of Tetracyanoquinodimethane

Diastereoselective Synthesis of 2,6‐Diaryltetrahydrothiopyran‐4‐ones by Phase‐Transfer Catalysis

“…Such products have been successfully used as laser dyes, organic conductors or as electrophotographic elements in xerography processes. [5][6][7] In total synthesis, 2,6-DATHTPs have been used in the synthesis of fused heterocyclic systems, and novel spirocycles have also been synthesized starting from 2,6-DATHTPs ( Figure 1, compound III). [8,9] 2,6-DATHTPs have also been considered as promising compounds for the treatment of several pathologies.…”

“…[10,13,15,16] However, three major issues limit the use of the protocol: 1) the high toxicity and unpleasant odour of gaseous H 2 S, 2) the lack of chemoselectivity, for example, DAAs bearing halogen substituents undergo sulfur-mediated aromatic nucleophilic substitution [17] and 3) the lack of stereoselectivity in the formation of 2,6-DATHTP [meso cis vs. racemic (Ϯ)-trans] [18] resulting in mixtures of the cis isomer as the major product and the trans isomer as the minor product. [6] Consequently, although a few cis isomers have been described, trans isomers have never been thoroughly studied and characterized. Having addressed these challenges, we present the…”

Heteroaromatic Analogues of Dibenzylideneacetone (dba) and Pd02(het-dba)3 Complexes: Effect of a Thienyl Moiety on the Reactivity of Pd0(η2-thn-dba)(PPh3)2/Pd0(PPh3)2 (n = 1 or 2) and Pd0(η2-th2-dba)(dppe)/Pd0(dppe) in Oxidative Addition Reactions with Iodobenzene

“…Arguably the most efficient means is by Claisen−Schmidt condensation of an appropriate aldehyde and ketone in the presence of NaOH in aqueous EtOH (Scheme ). The reaction of 2 equiv of thiophene-2-carbaldehyde or furan-2-carbaldehyde with acetone in the presence of NaOH in EtOH affords the symmetrical het-dba analogues 2a and 2b in 93% and 90%, respectively (eq ) . Unsymmetrical het-dba analogues were prepared by a similar reaction of one equiv of thiophene-2-carbaldehyde or furan-2-carbaldehyde with ( E )-4-phenylbut-3-en-2-one, affording 3a and 3b in 93% and 99%, respectively (eq ).…”

Simple Synthesis of β-Acetoxy Thiocyanates from Oxiranes

“…The starting 2-(arylsulfonylmethyl)oxiranes 1e-g were prepared in excellent yields (84-95%) by oxidation of the corresponding arylsulfanylglycidyl ethers with Oxone as the oxidant. The employed procedure was known, [30] but we lowered the temperature of the reaction. For oxiranes 1c-g, the reactions with ammonium thiocyanate were carried out with addition of hydroquinone.…”