Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• . A plausible mechanism is proposed, suggesting a possible radical pathway. Keywords: electrophilic amination; hypervalent iodine reagents; sulfinamide; sulfonamide; Introduction Iodine(III) compounds, known as λ3-iodanes, have been extensively applied in organic synthesis. Although initially used

• oxidation of sulfinamide 6aa by dissolved oxygen molecules in the media. Therefore, an additional experiment was conducted using sodium benzenesulfinate to simulate the potential in situ oxidation of the sulfenate anion before the addition of BBX 2a, but only trace amounts of sulfonamide 5ea were observed

• these conditions, no amine-transfer products 5aa (sulfonamide) or 6aa (sulfinamide) were observed. Next, and with the optimized conditions in hand (Table 1, entry 7), we studied the scope of the reaction by varying both the β-sulfinyl esters 4 and the electrophilic amines 2. Thus, a variety of

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• )acrylates in hands, we carried out an initial survey of their reaction with Et2Zn in CH2Cl2 at −33 °C on addition of air. In these conditions, acrylate 10 led to the recovery (following aqueous work-up) of sulfinamide 9 without traces of formation of the 1,4-adduct (Scheme 4). By contrast, 1,4-addition

Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

• Marco Manenti,
• Leonardo Lo Presti,
• Giorgio Molteni and
• Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

• . Interestingly, the molecule does not bear any pseudo-mirror plane, that is, the observed conformer is asymmetric (C1) in itself, regardless the configuration of the two sulfinamide substituents. This peculiarity is likely due to the hindered rotation across the newly formed C–C bond, joining the two oxindole

• units. Such the C2–C10 single bond is quite long (1.58 Å), as expected due to crowding of the two facing oxindole systems. In the crystal, NH groups set up intramolecular hydrogen bonds with the O acceptors of the sulfinamide moieties (see Table 2), likely contributing to further stabilize the observed

• ) and one sulfinamide oxygen (O4). Atom numbering as in Figure 1. The asymmetry of such interactions reflects the intrinsic asymmetry of the solid-state conformer. Supporting Information Supporting Information File 42: Experimental part, NMR spectra and christallographic data of compound 2a.

N-Sulfinylpyrrolidine-containing ureas and thioureas as bifunctional organocatalysts

• Viera Poláčková,
• Dominika Krištofíková,
• Boglárka Némethová,
• Renata Górová,
• Mária Mečiarová and
• Radovan Šebesta

Beilstein J. Org. Chem. 2021, 17, 2629–2641, doi:10.3762/bjoc.17.176

• /mismatched combination of chirality, we employed both enantiomers of tert-butyl sulfinamide with the (S)-enantiomer of the pyrrolidine building block. The introduction of green chemistry principles into chemical transformations is an important goal toward sustainable production and manufacturing. Asymmetric

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• %) from allylic sulfonamides 40 and Togni’s reagent (41). The reaction mechanism is proposed based on DFT calculations. In this study, they observed an intramolecularly intermediate Cu(III) species, and the sulfinamide acts as a direction group and nucleophile [75] (Scheme 14). Asymmetric synthesis of

• single diastereoisomer [126]. The diastereoselectivity of the addition was controlled in this case by both the α-siloxyl group and the chiral sulfinamide moiety. Interestingly, the utility of this approach was also demonstrated by the synthesis of (+)-febrifugine (133), a natural product isolated from

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• mechanism, where the sulfinamide is oxidized by ammonium persulfate to the respective sulfur-centred cationic intermediate. After electrophilic aromatic substitution, the amine moiety is cleaved and the corresponding sulfoxide is formed. The mechanistic proposal is supported by competition experiments using

• two arenes with different nucleophilicity, which were reacted with one sulfinamide. The respective product with the stronger nucleophile is formed exclusively. In reactions with two arenes having similar nucleophilicity a mixture of the respective products was obtained. Sulfonyl halides and

Quinone-catalyzed oxidative deformylation: synthesis of imines from amino alcohols

• Xinyun Liu,
• Johnny H. Phan,
• Benjamin J. Haugeberg,
• Shrikant S. Londhe and
• Michael D. Clift

Beilstein J. Org. Chem. 2017, 13, 2895–2901, doi:10.3762/bjoc.13.282

• , entries 8−10). Unfortunately, only sulfinamide 6t provided the desired imine 7t (Table 3, entry 10, 22% yield). In all three cases, a significant amount of benzaldehyde was observed, indicating that electron deficient primary amides (such as 6r−t) are either incapable of promoting transimination, or the

Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics

• Matthias Wünsch,
• David Schröder,
• Tanja Fröhr,
• Lisa Teichmann,
• Sebastian Hedwig,
• Nils Janson,
• Clara Belu,
• Jasmin Simon,
• Shari Heidemeyer,
• Philipp Holtkamp,
• Jens Rudlof,
• Lennard Klemme,
• Alessa Hinzmann,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2017, 13, 2428–2441, doi:10.3762/bjoc.13.240

• sulfinamide provides chiral N-sulfinylimines, which were reacted with (trimethylsilyl)ethynyllithium to afford diastereomerically pure N-sulfinyl propargylamines. Diverse functional groups present in the propargylic position resemble the side chain present at the Cα of amino acids. Whereas propargylamines

• groups is accessible for the use as precursors of peptidomimetics. Keywords: amino acid analogous side chains; desilylation; Ellman’s chiral sulfinamide; intramolecular Huisgen reaction; peptidomimetics; propargylamines; rearrangement to α,β-unsaturated imines; Introduction Terminal alkynes display an

• chiral sulfinamide auxiliary to produce diastereomerically pure amines [7]. Ellman’s chiral sulfinamide can be readily synthesized on a laboratory scale [24]. Moreover, sulfinamides can be cleaved easily under acidic conditions [1][25][26] and the produced sulfinic acid can even be recycled [25][27

Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds

• M. Fernanda N. N. Carvalho,
• Rudolf Herrmann and
• Gabriele Wagner

Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122

• , to give a cyclic sulfinamide 6 (Scheme 2b) [26]. In this case, the mechanism of the reaction proceeded through cationic intermediates as evidenced by in situ NMR spectroscopy. Catalysis by Pt(II) can drive the reaction even further: besides annulation and sulphur reduction, one finds a cleavage of

• , the sulfonamide group was reduced to a sulfinamide in the course of the reaction, and one of the former alkynyl carbons was oxidised to a ketone. The presence of the sulfinamide can be deduced from the fragmentation pattern in the mass spectrum where the loss of SO can be seen which is further

• in 22a. The IR spectrum also shows the presence of two carbonyl groups at 1680 and 1611 cm−1, and these are further confirmed in the 13C NMR spectrum (signals at 198.3 and 210.8 ppm). The NH of the sulfinamide seems to be strongly involved in hydrogen bonding with the carbonyl group nearby, as

Modular synthesis of the pyrimidine core of the manzacidins by divergent Tsuji–Trost coupling

• Sebastian Bretzke,
• Stephan Scheeff,
• Felicitas Vollmeyer,
• Friederike Eberhagen,
• Frank Rominger and
• Dirk Menche

Beilstein J. Org. Chem. 2016, 12, 1111–1121, doi:10.3762/bjoc.12.107

• precursor 5 for the envisioned Tsuji–Trost cyclization. As shown in Scheme 6, this involved an acidic cleavage of the sulfinamide followed by basic treatment to give free amine 35. After protection of the primary hydroxy group as TBS ether, we first evaluated the synthesis of derivative 40, in analogy to

• further studies for modular heterocycle synthesis. Experimental Preparation of 31 by asymmetric addition of allylmagnesium bromide to 29 In a flame-dried flask (SS)-N-(1-((tert-butyldimethylsilyl)oxy)propan-2-ylidene)-2-methylpropane-2-sulfinamide (29, 1.37 g, 4.70 mmol, 1.0 equiv) was dissolved in 12 mL

A novel and practical asymmetric synthesis of dapoxetine hydrochloride

• Yijun Zhu,
• Zhenren Liu,
• Hongyan Li,
• Deyong Ye and
• Weicheng Zhou

Beilstein J. Org. Chem. 2015, 11, 2641–2645, doi:10.3762/bjoc.11.283

• desired sulfinamide 5 was obtained only in a yield of 28%. The amount of denaphthalenyloxy was greatly reduced when the reaction temperature was decreased to −30 °C (Table 1, entry 2), but no significant improvement was achieved by further decreasing the temperature (Table 1, entry 3). It was assumed that

• recorded with an Agilent 1100 Series spectrometer. Preparation of (S)-2-methyl-N-(3-(naphthalen-1-yloxy)-1-phenylpropylidene)propane-2-sulfinamide (4): To a solution of 3 (30 g, 0.11 mol) and (S)-tert-butanesulfinamide (14.7 g, 0.12 mol) in THF (300 mL), Ti(OEt)4 (61.8 g, 0.22 mol) was added under N2

• , 402.1493. Preparation of (S)-2-methyl-N-((S)-3-(naphthalen-1-yloxy)-1-phenylpropyl)propane-2-sulfinamide (5): To a suspension of 4 (20 g, 53 mmol) in diisopropyl ether (300 mL), BH3/THF (10 mL, 42.2 mmol) was added dropwise at −5 to 0 °C. After this addition, the reaction mixture was stirred for 1.5 h. The

Direct access to pyrido/pyrrolo[2,1-b]quinazolin-9(1H)-ones through silver-mediated intramolecular alkyne hydroamination reactions

• Hengshuai Wang,
• Shengchao Jiao,
• Kerong Chen,
• Xu Zhang,
• Linxiang Zhao,
• Dan Liu,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2015, 11, 416–424, doi:10.3762/bjoc.11.47

• -insertion reaction [7], the cycloaddition of anthranilic acid iminoketene to a methyl butyrolactam through a sulfinamide anhydride intermediate [9], the intramolecular aza-Wittig reaction with an azide substrate [10], and the cycloaddition of anthranilamide [11]. For the synthesis of vasicinone (5

Enantioselective reduction of ketoimines promoted by easily available (S)-proline derivatives

• Martina Bonsignore,
• Maurizio Benaglia,
• Laura Raimondi,
• Manuel Orlandi and
• Giuseppe Celentano

Beilstein J. Org. Chem. 2013, 9, 633–640, doi:10.3762/bjoc.9.71

• involves the formation of a hydrogen-bond between the amide group of the catalyst and the substrate as a necessary element for stereocontrol (for another example of relevant N-formyl proline derivative see [12]). Also in Sun catalysts F [13][14] and sulfinamide G [15] as well as in chiral picolinamides H

A novel asymmetric synthesis of cinacalcet hydrochloride

• Veera R. Arava,
• Laxminarasimhulu Gorentla and
• Pramod K. Dubey

Beilstein J. Org. Chem. 2012, 8, 1366–1373, doi:10.3762/bjoc.8.158

• )-tert-butanesulfinamide and regioselective N-alkylation of the naphthyl ethyl sulfinamide intermediate is described. Keywords: asymmetric synthesis; (R)-tert-butanesulfinamide; cinacalcet hydrochloride; naphthyl ethyl sulfinamide; regioselective N-alkylation; Introduction Cinacalcet hydrochloride

• alcohol intermediate 12 from 10. Synthesis of bromo 5 and iodo 6 derivatives. Regioselective N-alkylation of naphthyl ethyl sulfinamide 4a. Acid hydrolysis of N-tert-butanesulfinyl group in 7. Screening of reduction conditions (9→10). Conditions for regioselective N-alkylation of naphthylethylsulfinamide

Thermal rearrangement of tert-butylsulfinamide

• Veera Reddy Arava,
• Laxminarasimhulu Gorentla and
• Pramod Kumar Dubey

Beilstein J. Org. Chem. 2011, 7, 9–12, doi:10.3762/bjoc.7.2

• observation, i.e., when sulfinamide 1 was reacted with an organic acid in the presence of boric acid [3] to obtain an amide 2 (Scheme 1), no amide was obtained, which was confirmed by IR and NMR data, and the product was also devoid of an acid residue. The product appeared to be derived only from the reagent

Synthesis of sulfonimidamides from sulfinamides by oxidation with N-chlorosuccinimide

• Olga García Mancheño and
• Carsten Bolm

Beilstein J. Org. Chem. 2007, 3, No. 25, doi:10.1186/1860-5397-3-25

• exploring an alternative and general procedure for the synthesis of these molecules avoiding the use of potential explosive reagents. Results and discussion For the preliminary screening, N-benzoyl sulfinamide 1a was chosen as the model substrate (Scheme 2). First, the reaction of 1a with different

• , the qualitative formation of sulfonimidoyl chloride 2a and its conversion to sulfonimidamide 3a could easily be followed by TLC. Subsequently, the role of the substituent at the sulfinamide nitrogen was examined. The reactivity of N-benzoyl, -benzyl and -tert-butyl carbamate protected sulfinamides 1a

• ). The best result was obtained with N-benzoyl sulfinamide 1a (94%, Table 1, Entry 12). However, reaction of N-Boc derivative 1c also gave the desired product 3c in good yield (78%, Entry 14). On the other hand, N-benzyl derivative 1b led to 3b in only moderate 56% yield (Entry 13). Therefore, benzoyl