Synthesis and Structural Comparison of Triaryl(sulfonylimino)pnictoranes

Abstract

Triarylphosphanes 1 (Ar(3)P; Ar = Ph, 4-MeC(6)H(4)), triphenylarsane (2), and triarylstibanes 3 (Ar(3)Sb; Ar = 2-MeC(6)H(4), 2-MeOC(6)H(4)) reacted with trifluoromethanesulfonamide (7a) in the presence of equimolar diethyl azodicarboxylate to afford the corresponding triaryl(sulfonylimino)pnictoranes [Ar(3)M=NSO(2)CF(3); 8 (M = P), 9 (M = As), 10 (M = Sb)]. The Kirsanov-type reaction of triarylantimony dichlorides 5 (Ar(3)SbCl(2); Ar = 2-MeC(6)H(4), 2-MeOC(6)H(4)) and triarylbismuth dichlorides 6 (Ar(3)BiCl(2); Ar = 2-MeC(6)H(4), 2-MeOC(6)H(4), 2,4,6-Me(3)C(6)H(2)) with sulfonamides 7 (H(2)NSO(2)R; R = CF(3), 4-MeC(6)H(4), Me) in the presence of 2 equiv of potassium tert-butoxide yielded triaryl(sulfonylimino)-lambda(5)-stibanes 10 and -bismuthanes 11, respectively. The ortho-substitution in aryl ligands of 10 and 11 has been found to bring about considerable kinetic stabilization of the reactive Sb=N and Bi=N bonds. A structural comparison was made for a series of triaryl(sulfonylimino)pnictoranes 8-11 by IR spectroscopy and X-ray crystallography. In the IR spectra of 9-11, SO(2) asymmetric stretching absorptions (nu(SO2)) were observed at lower wavenumbers as compared to those of phosphorus counterparts 8. The difference in frequency (Deltanu(SO2)) from 8 increased progressively as the pnictogen element being utilized moved down the group 15 column on the periodic table. X-ray crystallographic analyses of eight of the triaryl(sulfonylimino)pnictoranes prepared confirmed the increasing single-bond character of the M=N bond, with the contribution from the canonical structure M(+)-N=S(O)-O(-) increasing in importance in the order P < As < Sb < Bi. Among all triaryl(sulfonylimino)pnictoranes examined, only imino-lambda(5)-bismuthanes 11 oxidized alcohols to carbonyl compounds.

Synthesis, Structure, Reactivity, and Catalytic Activity of C,N‐ and C,N,N‐Orthopalladated Iminophosphoranes

“…Complex 11 does not react with Tl(acac) under the usual experimental conditions (room temperature, 1:1 molar ratio), and unchanged 11 can be recovered at the end of the reaction. However, the reaction of 11 with AgClO 4 and Ph 2 PCH 2 PPh 2 (dppm), Ph 2 PCH 2 CH 2 PPh 2 (dppe), 1,10-phenanthroline (phen) or 2,2Ј-bipyridine (bipy) (1:1:1 molar ratio) in acetone gives complexes of stoichiometry (15), dppe (16), bipy (17), phen (18)], in keeping with their elemental analyses and mass spectra. The IR spectra of 15-18 show the absorption due to the ν PN stretch in the range 1330-1340 cm -1 , thereby suggesting that the Pd-N-(imine) bond is still present.…”

“…The best reaction solvent for this type of process was found to be DMF. In spite of its similarity, very poor yields were obtained when N,Ndimethylacetamide (DMA) was used (entries 1-4 vs. entries [15][16][17][18], and the reaction was completely inhibited in NMP (N-methylpyrrolidinone). A comparison of the different catalysts shows that complexes 1 and 4 give better conversions than complexes 11 or 13, and this fact could be related to the presence of the highly stable terdentate ligand [C 6 H 4 -2-PPh 2 =N-C(O)-2-NC 5 H 4 -κ-C,N,N] in 11 and 13 (see below).…”

A mini review on chemical fixation of CO2: Absorption and catalytic conversion into cyclic carbonates

“…[5][6][7][8]. In the past decade, there has been a rapid development on bismuth chemistry [9][10][11][12][13][14][15][16][17]. There are various researches on novel cationic organobismuth complexes and their applications [16][17][18][19][20][21][22][23].…”

Computational Chemistry Study of CO2Fixation and Cyclic Carbonate Synthesis Using Various Catalysts

“…이 반응은 단점이 있는데 높은 활성화 에너지(activation energy)를 가지기 때문에(55~59 kcal/mol) 높 은 발열(exothermic)에도 불구하고 비촉매 상태에서는 자발적 으로 반응이 일어나지 않는다는 것이다 [7]. 그로 인해 지난 수 십 년간 포스핀 [8][9][10], 유기염기 [11], 이온성 액체 [12][13][14][15][16][17], 유 기금속착물 [18][19][20][21], 금속산화물 [22][23][24], 담지된 촉매 [25][26][27] [28], 암모늄염(ammonium salt) [29], 금 속 할로겐염(metal halide salt) [30], 알카놀아민(alkanolamine) [31]. 본 논문에서는 본 연구팀에 의해 타 문헌에 제시된 반응 메커니즘들을 새로이 에너지도(energetics)로 통합하여 정리 …”