Intramolecular hydroamination of alkynic sulfonamides catalyzed by a gold–triethynylphosphine complex: Construction of azepine frameworks by 7-exo-dig cyclization

• Hideto Ito,
• Tomoya Harada,
• Hirohisa Ohmiya and
• Masaya Sawamura

Beilstein J. Org. Chem. 2011, 7, 951–959, doi:10.3762/bjoc.7.106

• Hideto Ito Tomoya Harada Hirohisa Ohmiya Masaya Sawamura Department of Chemistry, Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan 10.3762/bjoc.7.106 Abstract The gold-catalyzed, seven-membered ring forming, intramolecular hydroamination of alkynic sulfonamides has been

• heterocyclic seven-membered rings, and we applied the triethynylphosphine–gold(I) catalytic systems to the synthesis of azepine derivatives through intramolecular hydroamination of alkynic sulfonamides. This article describes the results of the optimization of reaction conditions, exploration of substrate

• that the 7-exo-dig intramolecular hydroamination of ω-alkynic N-alkyl-N-sulfonamides is efficiently catalyzed by a gold(I) complex coordinated with the semihollow-shaped triethynylphopshine ligand L1, and that the cyclization protocol provides a new efficient route to N-containing seven-membered ring

Synthetic applications of gold-catalyzed ring expansions

• David Garayalde and
• Cristina Nevado

Beilstein J. Org. Chem. 2011, 7, 767–780, doi:10.3762/bjoc.7.87

• in the presence of sulfonamides [24]. Phenylcyclopropylalcohol 21 was efficiently transformed into sulfonyl pyrrolidine 23 in the presence of 5 mol % of the cationic complex AuOTf (Scheme 7). The reaction was applicable to a wide range of activated and non-activated cyclopropylmethanols, sulfonamides

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

• and decarboxylation then affords sumatriptan [14]. All the reported methods for the synthesis of sumatriptan begin with the sulfonamide group already present on the aromatic ring and several routes are possible to introduce this functional group. The scalable route to the sulfonamides inevitably

• sulfonamides, all prepared in high yields. As this route employs sulfonamide-stabilised anions the preparation and handling of unstable sulfonyl chloride intermediates is therefore circumvented (Scheme 14) [17]. An analogous Heck reaction approach has also been employed to introduce a homologous side chain as

Approaches towards the synthesis of 5-aminopyrazoles

• Ranjana Aggarwal,
• Vinod Kumar,
• Rajiv Kumar and
• Shiv P. Singh

Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25

• starting from substituted sulfonamides 71. Sulfonamides 71 after diazotization undergo a coupling reaction with malononitrile to generate the hydrazones 72, which on cycloaddition with hydrazine hydrate give the corresponding pyrazoles (Scheme 19). Reaction of ketenes, particularly those with a cyano group

Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

• Carolin Fischer and
• Burkhard Koenig

Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10

• ], benzimidazoles [40][41], sulfonamides [38], pyrroles [42] and lactams [43]. The three typical methods for N-arylation have been extensively reviewed concerning scope and limitation of these reactions [4][44][45][46][47][48]. However, the application of palladium- and copper-mediated N-arylation reactions in the

Aromatic and heterocyclic perfluoroalkyl sulfides. Methods of preparation

• Vladimir N. Boiko

Beilstein J. Org. Chem. 2010, 6, 880–921, doi:10.3762/bjoc.6.88

• disulfides under irradiation or on mild heating to give the corresponding trifluoromethyl sulfides (Scheme 54). The N- trifluoromethylnitrososulfonamide of trifluoromethane sulfonic acid reacts similarly with aliphatic disulfides [214]. Interaction of CF3NO with aryl sulfonamides generates relatively stable

Recent advances in carbocupration of α-heterosubstituted alkynes

• Ahmad Basheer and
• Ilan Marek

Beilstein J. Org. Chem. 2010, 6, No. 77, doi:10.3762/bjoc.6.77

• centers. Carbocupration of alkynyl sulfonamide. Tandem carbocupration-sigmatropic rearrangement. Silylcupration of alkynyl sulfonamides. Carbocupration of P-substituted alkynes. Carbocupration of alkynylphosphonates. Carbocupration of thioalkynes. Tandem carbocupration-1,2-metalate rearrangement

Anion receptors containing thiazine-1,1-dioxide heterocycles as hydrogen bond donors

• Hong-Bo Wang,
• James A. Wisner and
• Michael C. Jennings

Beilstein J. Org. Chem. 2010, 6, No. 50, doi:10.3762/bjoc.6.50

• anions can be attributed to greater steric demand in the cleft formed, in part, by its terminal phenyl rings; an effect that is absent in the comparison receptor. Keywords: anions; hydrogen bonds; receptors; sulfonamides; supramolecular chemistry; Introduction The synthesis of neutral hosts and study

• of nitrogen-based hydrogen bond donor groups such as amides [3][4], ureas [5], pyrroles/indoles/carbazoles [6][7] and sulfonamides [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23] to complex the anionic targets in a topologically complementary fashion. Sulfonamides are an interesting

• case as the hydrogen bond donor is often significantly more acidic (pKa approx. 11 for simple N-phenylaryl sulfonamides such as 3 (see below)) than that presented by other groups typically incorporated in these frameworks. The greater acidity of such a subunit can be an advantage by providing greater

Diastereoselective functionalisation of benzo-annulated bicyclic sultams: Application for the synthesis of cis-2,4-diarylpyrrolidines

• Susan Kelleher,
• Pierre-Yves Quesne and
• Paul Evans

Beilstein J. Org. Chem. 2009, 5, No. 69, doi:10.3762/bjoc.5.69

• place to afford cis-2,4-diaryl-substituted pyrrolidines 35–37. Keywords: cyclic sulfonamides; diastereoselective alkene functionalisation; double reduction; Pd-mediated cross coupling; Introduction Substituted pyrrolidine ring systems represent a common structural motif in a range of biologically

• active compounds, including pharmaceutical agents and natural products. In relation to these general targets, we have recently developed a method that enables the construction of aryl-substituted pyrrolidines, featuring the double reduction of cyclic aromatic sulfonamides [1][2][3][4]. As illustrated in

• preparation of 2,4-diaryl-substituted pyrrolidines from more readily available, albeit racemic, substrates. Results and Discussion Bicyclic aromatic cyclic sulfonamides 5a and 5b were formed according to the 3-step sequence previously described [1][2][3][10]. Originally, inclusion of triphenylphosphine was

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• ]paracyclophane compounds; aryl sulfonylation and the related sulfenylation facilitates the synthesis of sulfonic acids, sulfonamides and protected thiols [24][25][26] whilst directed metallation has allowed the formation of various sulfides [27][28][29][30]. Very few methodologies allow the synthesis of simple

N-Arylation of amines, amides, imides and sulfonamides with arylboroxines catalyzed by simple copper salt/EtOH system

• Zhang-Guo Zheng,
• Jun Wen,
• Na Wang,
• Bo Wu and
• Xiao-Qi Yu

Beilstein J. Org. Chem. 2008, 4, No. 40, doi:10.3762/bjoc.4.40

• , imides and sulfonamides catalyzed by a copper salt/EtOH system has been developed. In the absence of a base or additive the corresponding N-arylation products were obtained in moderate to excellent yields. Keywords: N-arylation; arylboroxine; copper salt; cross-coupling; ethanol; Introduction The

• ). Furthermore, we expand the substrate scope of this reaction: a variety of amines, amides, imides and sulfonamides with arylboroxine can also participate in this catalytic system to give the corresponding N-arylation products in moderate to excellent yields. To the best of our knowledge, N-arylation of NH

• reaction. In an endeavor to expand the scope of the above methodology, the catalytic system was also applied to imides, amines, amides and sulfonamides. Such coupling was found to give the desired N-arylation products in moderate yields, as shown in Table 5, except for sulfonamide, which afforded the

The enantiospecific synthesis of (+)-monomorine I using a 5-endo- trig cyclisation strategy

• Malcolm B. Berry,
• Donald Craig,
• Philip S. Jones and
• Gareth J. Rowlands

Beilstein J. Org. Chem. 2007, 3, No. 39, doi:10.1186/1860-5397-3-39

• tosyl moiety as the nitrogen-protecting group (PG) and resulted in a succinct synthesis of alkenes of the type 4 (X = NTs; Scheme 1). [15] Disappointingly, all attempts to ring-close the sulfonamides proved fruitless, and it was found that desulfonylation was necessary before cyclisation could be

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

• % yield. Conclusion A convenient alternative procedure for the synthesis of sulfonimidamides from sulfinamides and various amines and sulfonamides using N-chlorosuccinimide as halogenating agent has been developed. Introduction Sulfonimidamides 3 are derivatives of sulfonic acid and analogous of

• sulfonamides, in which one oxygen has been replaced by a nitrogen group. They are known since 1962,[1] and a number of recent investigations focussed on both their reactivity and application in organic synthesis, such as nitrogen sources for metal-catalyzed nitrene transfer reactions, [2][3][4][5] and their