Intramolecular sulphonamidomethylation. Part II. Fused heterocycles from 2‐phenylethanesulphonamides

Abstract

1,2,4,5‐Tetrahydro‐3,2‐benzothiazepine 3,3‐dioxides 2, with a variety of substituents on the nitrogen atom, can be easily obtained by the title reaction. The isomeric compounds 4–6 are also formed from sulphonamides bearing an N‐aralkyl group with a chain of two or more carbon atoms. Activation of the ring closure‐position or deactivation of the aromatic ring in the substituent can direct the reaction to give compounds 2. Cyclization results are influenced by the size of the new heterocycle ring and by the predominant formation of derivatives with the SO2 group outside the ring.

Sulfated Zirconia as an Efficient Catalyst for Sulfonylamidomethylation of Benzylsulfonamides and 2-Phenylethanesulfonamides: Effect of Catalyst Thermal Treatment

“…The benzylsulfonamides 1 and 2-phenylethanesulfonamides 3 were prepared from the corresponding benzyl and 2-phenylethyl halides following a general method [11,12]. Commercial SO 4 2-/ZrO 2 from Mel Chemical Co was dried at 110°C for 2 h in air and was subsequently calcined for 5 h in air atmosphere between 250 and 800°C.…”

“…Reagent grade solvents were used; 1,1,2-trichloroethane and 1,1,2,2-tetrachloroethane were distilled over phosphorous pentoxide and stored over 4 Å Molecular Sieves. The purity of the isolated compounds was checked by comparison with authentic samples prepared according to known procedures ( 1 HRMN spectra, m.p., TLC) [11,12,19]. The known reaction products were characterized by melting point and 1 HNMR spectra.…”

“…A similar approach was subsequently applied for the construction of 1,2,4,5-tetrahydro-3,2-benzothiazepine 3,3-dioxides 4 from 2-phenylethanesulfonamides 3 using methanesulfonic acid and trifluoroacetic acid as catalyst with good yield (Scheme 2) [12]. Up to now, no other method was found for the preparation of 3,2-benzothiazepine 3,3-dioxide with the exception of 1-ethoxy-2,4,5-trihydro-3,2-benzothiazepine 3,3-dioxide, which was prepared in several steps [13].…”

Rh-catalyzed asymmetric 1,4-addition reactions to α,β-unsaturated carbonyl and related compounds: an update

“…Based on this transformation, the first stereoselective total synthesis of cherylline was disclosed. [205][206][207][208][209][210][211][212] An efficient (S/C, substrate/catalyst, up to 500) Rh-catalyzed addition of diverse arylboronic acids 2 to 2-nitrostyrenes 180a-l under mild reaction conditions was reported, which gave excellent chemical yields (up to 99%) and enantioselectivities (up to 98% ee) via using tert-butanylsulfinylphosphine as a ligand (Table 65). This approach provides a promising route for the synthesis of chiral 2,2-bisarylethylamines 208a-y with excellent chemical yields and ee (Scheme 103).…”

Sulfonilamidometilación intramolecular de 2-naftilmetan y 2-(2-naftil)etansulfonamidas

“…Se obtuvieron así 1,2,4,5-tetrahidro-3,2-benzotiazepinas 3,3-dióxido (29) utilizando trioxano como fuente formaldehído en medio ácido homogéneo. (39)…”