An efficient copper-catalyzed synthesis of symmetrical bis(N-arylbenzamide) selenides and their conversion to hypervalent spirodiazaselenuranes and hydroxy congeners

Abstract

A copper catalyzed efficient synthetic method has been developed to access bis(N-arylbenzamide) selenides from 2-halo-N-arylbenzamide substrates and disodium selenide in HMPA at 110 °C.

Tetravalent Spiroselenurane Catalysts: Intramolecular Se···N Chalcogen Bond-Driven Catalytic Disproportionation of H2O2 to H2O and O2 and Activation of I2 and NBS

“…bis -(2-Benzamide) selenides 1 – 3 and spiroselenurane 4 – 6 were characterized by multinuclear ( 1 H, 13 C, 77 Se) NMR and mass spectroscopy. The 77 Se NMR of 4 – 6 shows a significant downfield shift (δ 645–655 ppm) as compared to the reported tetracoordinated Se­(IV) selenuranes (δ 550–595 ppm) . Interestingly, the chemical shifts are comparable to the earlier reported penta-coordinated Se­(VI) spiroselenoxy analogs (δ 644–702 ppm), , which suggest a strong Se···N interaction in solution in 4 – 6 .…”

“…The tetravalent organo-spiroselenuranes were first reported by Lesser and Weiss in 1914, mainly studied for their optical properties, and also recently studied as a mimic of the GPx for the reduction of hydrogen peroxide by organothiol reductant . Similar to the above documented organoselenium GPx mimics, spiroselenuranes also required a thiol co-reductant for the reduction of oxidant hydrogen peroxide.…”

Synthesis and antioxidant activities of N-thiophenyl ebselenamines: a 77Se{1H} NMR mechanistic study

“…23 Inspired by ebselen as the most redox active small molecule, several other important biologically active organoselenium compounds have been reported including ebselen analogues and other derivatives. 24–26…”

A base-free copper-assisted synthesis of C2-symmetric spirotelluranes and biaryls based on divergent stoichiometry of Na2Te

“…Here, in continuation of our work on organochalcogen chemistry, 20,21 particularly on organotelluriums, 15,20 we report a base-free copper-assisted single step methodology for tetravalent spirotelluranes derived from benzamide, phenylmethyl alcohol and benzoic acid substrates and the telluride dianion. Furthermore, the use of an excess of telluride dianion led to C–C coupled biaryl 1,1′-diamides under the same reaction conditions.…”

“…Next, synthesized spirotelluranes 1k , 1m–1o , and 1p have been tested for the H 2 O 2 decomposing GPx-like activity by following the established assay (eqn (1) and Table S2, ESI,† pages S36 and S37). 6 a ,21 The chalcogen-bonded spirotelluranes 1n–1p catalyzed the thiol oxidation reaction at faster reduction rates ( ν o = 80.2 ± 3.0, 78.1 ± 2, and 78.3 ± 1.7 μM min −1 , respectively), as compared to standards Ph 2 Se 2 , 21 ebselen ( ν o = 24.1 ± 2 and 22.3 ± 2.1 μM min −1 ) and the tested spirotelluranes 1k and 1m ( ν o = 28.2 ± 1.8 and 27.8 ± 1.6, μM min −1 ), respectively.…”