Lewis-base stabilized diiodine adducts with N-heterocyclic chalcogenamides

Abstract

Oxidation reactions of stable chalcogenamides with iodine are intriguing due to their broad application in various organic syntheses. In the present study we report on the utilization of N-heterocyclic carbene and cyclic-alkyl-amino carbenes L(1-3): (L(1): = :C[N(2,6-iPr2-C6H3)CH]2, L(2): = :C(CH2)(CMe2)(C6H10)N-2,6-iPr2-C6H3, L(3): = :C(CH2)(CMe2)2N-2,6-iPr2-C6H3) for the syntheses of chalcogenamides L(1-3)=E (E = S, Se, Te) 1-4 and zwitterionic adducts L(1-3)=E-I-I 5-8. The synthesis of compounds 1-4 involved the addition reaction of ligand L(1-3): and elemental chalcogen. Treatment of 1-4 with iodine resulted in the formation of adducts 5-8. Compounds 5-8 are well characterized with various spectroscopic methods and single-crystal X-ray structural analysis.

Cyclic (Alkyl)(Amino)Carbene Complexes of Rhodium and Nickel and Their Steric and Electronic Parameters

“…These values are in good agreement with the observed A 1 carbonyl stretching frequency of [Ni(CO) 3 (CAAC methyl )] (8, TEP=ñ A1/Ni = 2046 cm À1 )a nd similar to those of the sterically more demanding menthyl-(TEP = 2042 cm À1 )a nd cyclohexyl-(TEP = 2049 cm À1 )s ubstituted CAACs (Table 1, entries 6, 8), obtained from the complexes cis-[IrCl(CO) 2 (CAAC menthyl )] (ñ av/Ir = 2013 cm À1 ) [4a] and cis-[RhCl(CO) 2 (CAAC cy )] (ñ av/Rh = 2036 cm À1 ), [3a] respectively.F urthermore, the TEP of 1 is similart ot hose of classical NHCs ( In marked contrast, the significantly low-field-shifted 77 Se NMR resonanceo ft he CAAC methyl -Se adduct (d Se = 492.4 ppm) [29] and the 31 PNMR resonance of the corresponding phosphinidene adduct 11 (d P = 67.2 ppm), which wasp repared according to the literature [11,30] (Scheme 8, Figure9), illustrate the highly electrophilicc haracter of 1 (Table 1, entry 7), which is only surpassed by those of acyclic (Table 1, entry 9) or Bielawski-type carbenes (Table1,e ntry 10). Since it gives rise to as imilar TEP value while having superior p-acceptor properties, carbene 1,l ike CAAC menthyl and CAAC cy (Table1,e ntries 6, 8), is proposed to be an otably stronger s-donort han common NHCs (Table 1, entries 1-4).…”

“…In marked contrast, the significantly low‐field‐shifted 77 Se NMR resonance of the CAAC methyl –Se adduct (δ Se =492.4 ppm) and the 31 P NMR resonance of the corresponding phosphinidene adduct 11 (δ P =67.2 ppm), which was prepared according to the literature (Scheme , Figure ), illustrate the highly electrophilic character of 1 (Table , entry 7), which is only surpassed by those of acyclic (Table , entry 9) or Bielawski‐type carbenes (Table , entry 10). Since it gives rise to a similar TEP value while having superior π‐acceptor properties, carbene 1 , like CAAC menthyl and CAAC cy (Table , entries 6, 8), is proposed to be a notably stronger σ‐donor than common NHCs (Table , entries 1–4).…”

A soluble molecular variant of the semiconducting silicondiselenide

“…Orange powders of 3a–b decompose above 285 °C ( 3a ), 245 °C ( 3b ) to give light yellow solids of cAACSe. 17 This is concluded from mass spectrometry (see ESI†). Compound 3a was further characterized by EI-MS mass spectrometry ( m / z (100%); 944.2) (see ESI†).…”

Reactivity of a Stable Phosphinonitrene towards Small Molecules

“…[19] Addition of sulfur to a toluene solution of 1 cleanly led to 8, which was isolated after workup as red crystals in 56 % yield. An X-ray diffraction analysis revealed the presence of a thiosulfinylamino group bonded to the phosphorus atom ( Figure Stable singlet carbenes have shown diverse reactivity with white phosphorus leading to the degradation and aggregation of P 4 producing P 1 , P 2 , P 4 , P 8 , and P 12 fragments, depending on the nature of the carbene.…”