Protonation of Sulfinamides. Does It Occur at Oxygen or Nitrogen?

Bujnicki, Bogdan; Drabowicz, J.; Mikołajczyk, M.; Kolbe, A.; Stefaniak, L.

doi:10.1021/jo960205j

Cited by 19 publications

(15 citation statements)

References 21 publications

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“…From such results O-protonation was indicated as favored, but this conclusion was later challenged by Mikolajczyk et al [37] on the basis of IR, 15 N, and 13 C NMR measurements on some aryl (ArSONR 2 ) and Omethylated [ArS(OMe)NR 2 ] sulfinamides in nonaqueous solvents (e.g. HCl/CH 2 Cl 2 ).…”

Section: And Their Changes)mentioning

confidence: 99%

“…HCl/CH 2 Cl 2 ). As the discrepancy might actually arise from differences in base structure and solvent, [37] in order to provide a consistent basis for comparing the two sets of results, we calculated the same parameters for pyrrolidine, Table 3. Basicity of amides in the gas phase and in water (HF-IPCM and MP2 calculations).…”

Section: And Their Changes)mentioning

confidence: 99%

“…[9,11] On the other hand, Mikolajczyk et al [37] obtained 15 N and 13 C spectra of aryl sulfinamides (ArSONR 2 ) in nonpolar solvents (CH 2 Cl 2 , MeNO 2 ), and compared such protonation shifts with those of parent amines and of O-methylated derivatives [methoxyaminosulfonium salts, ArS(OMe)NR 2 ] assumed to model ArSONHR 2 and ArS(OH)NR 2 . However, the assumption that the difference in chemical shift between amine and ammonium ion, or sulfinamide and methoxyaminosulfonium ion, exactly model the sought quantities must be tested.…”

mentioning

confidence: 99%

“…Another tool employed [37] was the analysis of 13 C shifts. It was found that, upon protonation, the chemical shift of the pyrrolidine C-a in PhSONpyr follows the same trend as pyrrolidine, and opposite to that of PhS(OMe)Npyr .…”

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confidence: 99%

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Site of Protonation of Carboxylic and Non-Carboxylic Amides in the Gas Phase and in Water

et al. 1999

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The site of protonation of several types of amide bases (carboxylic amides and thioamides, sulfenamides, sulfinamides, sulfonamides, nitrosamides, nitramides, cyanamides, and phosphorous and phosphoric acid triamides) has been investigated through a combination of quantum chemical calculations and heteronuclear NMR measurements. Relative energies of tautomeric ions deriving from protonation at the various sites were determined both in the gas phase (by MP2 calculations) and in water (by the IPCM continuum solvation method). Relevant NMR properties of the involved heteronuclei (nuclear shielding and electric field gradient) were calculated at the GIAO-HF level, and compared with chemical shifts and relaxation rates experimentally measured in 14 N, 17 O, and 31 P spectra. It is shown that such a combination of theoretical and experimental tools allows a dependable prediction of spectral parameters and ultimately of the protonation site of amides. The reliability of common assumptions, like the comparison of spectral parameters of polyfunctional bases and monofunctional models, is also scrutinized and tested.

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Section: And Their Changes)mentioning

confidence: 99%

Section: And Their Changes)mentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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Site of Protonation of Carboxylic and Non-Carboxylic Amides in the Gas Phase and in Water

et al. 1999

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“…In this manner we were able to prepare high quality benzenesulfinyl piperidine in 86% yield on a 55 g scale. Similarly prepared on multigram scales were 1-benzenesulfinyl pyrrolidine (2), [17] N,N-diethyl benzenesulfinamide (3), [18] and N,N-dicyclohexyl benzenesulfinamide (4). Two of these sulfinamides (2 and 4) were crystalline with melting points bracketing that of BSP, while a third (3) was a free-flowing, distillable liquid.…”

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confidence: 99%

Improved Synthesis of 1‐Benzenesulfinyl Piperidine and Analogs for the Activation of Thioglycosides in Conjunction with Trifluoromethanesulfonic Anhydride*

Crich

Banerjee

et al. 2005

Journal of Carbohydrate Chemistry

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An improved protocol for the large scale production of 1-benzenesulfinyl piperidine and other sulfinamides is described. It is demonstrated that 1-benzenesulfinyl pyrrolidine and N,N-diethyl benzenesulfinamide function analogously to 1-benzenesulfinyl piperidine in the trifluoromethanesulfonic anhydride-mediated activation of thioglycosides, and that their less crystalline nature enables them to be used at −78 °C as opposed to the −60 °C required to keep 1-benzenesulfinyl piperidine in solution. N,N-Dicyclohexyl benzenesulfinamide does not activate thioglycosides in combination with trifluoromethanesulfonic anhydride which is attributed to its greater steric bulk.

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Highly Diastereoselective [3+2] Cycloadditions between Nonracemic p‐Tolylsulfinimines and Iminoesters: An Efficient Entry to Enantiopure Imidazolidines and Vicinal Diaminoalcohols

Viso

Pradilla

García

et al. 2003

Chemistry A European J

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A new procedure for the asymmetric synthesis of imidazolidines and vicinal diamines is reported. The 1,3-dipolar cycloaddition between nonracemic p-tolylsulfinimines and azomethine ylides generated in situ from alpha-iminoesters and LDA produces N-sulfinylimidazolidines with a high degree of stereocontrol. In contrast, the presence of Lewis acids promotes formation of the cycloadducts through a highly diastereoselective process with opposite stereochemistry. Subsequent transformations of the imidazolidines including oxidative, reductive, and hydrolytic processes that provide easy access to vicinal diaminoalcohols have been explored. Among these, reductive cleavage of the aminal with LiAlH4 is an extremely efficient and general reaction for the synthesis of enantiopure N-sulfinyl-N'-benzyldiaminoalcohols

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Protonation of Sulfinamides. Does It Occur at Oxygen or Nitrogen?

Cited by 19 publications

References 21 publications

Site of Protonation of Carboxylic and Non-Carboxylic Amides in the Gas Phase and in Water

Site of Protonation of Carboxylic and Non-Carboxylic Amides in the Gas Phase and in Water

Improved Synthesis of 1‐Benzenesulfinyl Piperidine and Analogs for the Activation of Thioglycosides in Conjunction with Trifluoromethanesulfonic Anhydride*

Highly Diastereoselective [3+2] Cycloadditions between Nonracemic p‐Tolylsulfinimines and Iminoesters: An Efficient Entry to Enantiopure Imidazolidines and Vicinal Diaminoalcohols

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