The first enantioselective catalytic approach to cis- and trans-2,3-diaryl substituted 1,5-benzothiazepines has been conveniently developed in a one-pot fashion, starting from α,β-unsaturated acyl pyrazoles and 2-aminothiophenol. The organocatalytic two-step sulfa-Michael/lactamization sequence is promoted by a readily available bifunctional thiourea and p-toluenesulfonic acid, respectively. The protocol enables access to both N-unprotected cis- and trans-diastereoisomers in moderate to satisfactory overall yields (up to 84%) and good to excellent ee values (up to 99%). Mechanistic investigations helped to shed light on the regio- and stereoselective outcome of the process.
Catalytic enantioselective one-pot approach to cis- and trans-2,3-diaryl substituted 1,5-benzothiazepines / Meninno, Sara*; Quaratesi, Ilaria; Volpe, Chiara; Mazzanti, Andrea; Lattanzi, Alessandra. - In: ORGANIC & BIOMOLECULAR CHEMISTRY. - ISSN 1477-0520. - STAMPA. - 16:38(2018), pp. C8OB01988F.6923-C8OB01988F.6934. [10.1039/C8OB01988F]
Catalytic enantioselective one-pot approach to cis- and trans-2,3-diaryl substituted 1,5-benzothiazepines
Mazzanti, Andrea;
2018
Abstract
The first enantioselective catalytic approach to cis- and trans-2,3-diaryl substituted 1,5-benzothiazepines has been conveniently developed in a one-pot fashion, starting from α,β-unsaturated acyl pyrazoles and 2-aminothiophenol. The organocatalytic two-step sulfa-Michael/lactamization sequence is promoted by a readily available bifunctional thiourea and p-toluenesulfonic acid, respectively. The protocol enables access to both N-unprotected cis- and trans-diastereoisomers in moderate to satisfactory overall yields (up to 84%) and good to excellent ee values (up to 99%). Mechanistic investigations helped to shed light on the regio- and stereoselective outcome of the process.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.