Cobalt(III)/Chiral Carboxylic Acid‐Catalyzed Enantioselective Synthesis of Benzothiadiazine‐1‐oxides via C−H Activation

Abstract

Among sulfoximine derivatives containing a chiral sulfur center, benzothiadiazine-1-oxides are important for applications in medicinal chemistry. Here, we report that the combination of an achiral cobalt(III) catalyst and a pseudo-C 2 -symmetric H 8 -binaphthyl chiral carboxylic acid enables the asymmetric synthesis of benzothiadiazine-1-oxides from sulfoximines and dioxazolones via enantioselective CÀ H bond cleavage. With the optimized protocol, benzothiadiazine-1-oxides with several functional groups can be accessed with high enantioselectivity.

Synthesis of Sulfur-Stereogenic Sulfoximines via Co(III)/Chiral Carboxylic Acid-Catalyzed Enantioselective C–H Amidation

“…The acyclic amidation product can be reduced to potential N,S -chiral sulfoxides, a type of S -stereogenic sulfoxide ligands with a second coordinating N atom, which could be further transformed into recyclable chiral auxiliaries in the Pd-catalyzed diastereoselective C­(sp 3 )–H activation of aliphatic substrates . It should be noted that similar work was reported by Matsunaga and co-workers during our preparation of this manuscript …”

“…14 It should be noted that similar work was reported by Matsunaga and co-workers during our preparation of this manuscript. 15…”

Recent Advances in the Synthesis of Cyclic Sulfoximines via C–H Bond Activation

“…In 2022, Yoshino and coworker described a protocol involving Cp*Co(CO)I 2 /chiral carboxylic acid 66 as a catalytic system, which promoted the C–H functionalization reaction of sulfoximines 62 with dioxazolone 63 for the enantioselective synthesis of benzothiadiazine-1-oxides 65 ( Scheme 28 ) [ 44 ]. This strategy consisted of two reaction steps.…”

Ruthenium(II)/Imidazolidine Carboxylic Acid‐Catalyzed C−H Alkylation for Central and Axial Double Enantio‐Induction

“…Key insights by Reutov on palladium-mediated stereoselective CÀ H activation were followed by subsequent studies by Yu. [11] In contrast, group 9 transition metals (TM = cobalt, [12] rhodium, [13] iridium [14] ) were devised for enantioselective CÀ H activations by among others Ackermann, Cramer, Matsunaga, Shi, and He. In this context, the use of chiral imidazolidine carboxylic acids (CICAs) in ruthenium catalysis was also disclosed by our group, thus achieving an enantioselective intramolecular hydroarylation.…”