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

Abstract

Sulfoximines, a ubiquitous class of structural motifs, are widely present in bioactive molecules and functional materials that have received considerable attention from modern organic chemistry, pharmaceutical industries, and materials science. Sulfoximines have proved to be an effective directing group for C-H functionalization which was widely investigated for the synthesis of cyclic sulfoximines. Within the last decade, great progress has been achieved in the synthesis of cyclic sulfoximines. Thus, this review highlights the recent advances in the synthesis of cyclic sulfoximines via the C-H activation strategy and is classified based on the substrate types.

Keywords: C–H activation; cyclic sulfoximines; cyclization; synthesis; synthetic methods.

Figure 1

Structures of bioactive cyclic sulfoximines and analogues.

Figure 2

The main strategies towards cyclic sulfoximines synthesis.

Scheme 1

Rhodium-catalyzed annulation reactions for the synthesis of 1,2-benzothiazines.

Scheme 2

Ir(III)-catalyzed C–H functionalization of sulfoximines with α-diazocarbonyl compounds.

Scheme 3

Proposed mechanism of the formation of 1,2-benzothiazines in the Ir(III) catalytic system.

Scheme 4

Synthesis of chiral-at-sulfur 1,2-benzothiazines via C–H functionalization of sulfoximines.

Scheme 5

Proposed mechanism of Rh-catalyzed chiral-at-sulfur 1,2-benzothiazines formation.

Scheme 6

Rhodium-catalyzed strategy for the enantiodivergent desymmetrization of sulfoximines.

Scheme 7

Sustainable Rh(III)-catalyzed C–H activation/cyclization of sulfoximines to form 1,2-benzothiazines.

Scheme 8

Proposed catalytic circle.

Scheme 9

Rh(III)-catalyzed C–H functionalization strategy for the kinetic resolution of racemic sulfoximines.

Scheme 10

Rh(III)-catalyzed method for the synthesis of fused 1,2-benzothiazines from sulfoximines and 4-diazoisochroman-3-imines.

Scheme 11

Proposed mechanism of the annulation between sulfoximines and 4-diazoisochroman-3-imines.

Scheme 12

Rh-catalyzed synthesis of highly conjugated 1,2-benzothiazine scaffolds.

Scheme 13

Ir(III)-catalyzed C–H activation/annulation strategy for the synthesis of chiral 1,2-benzothiazines.

Scheme 14

The synthesis of 1,2-benzothiazine through rhodium(III)-catalyzed annulative couplings.

Scheme 15

Proposed mechanism of the tandem annulative coupling between sulfoximines and sulfoxonium ylides.

Scheme 16

Desymmetrization, kinetic resolution, and parallel kinetic resolution of sulfoximines with sulfoxonium ylides under the Ru-catalyzed system.

Scheme 17

Rhodium-catalyzed strategy for the synthesis of polycyclic 1,2-benzothiazines from different aryl sulfoximines and iodonium ylides.

Scheme 18

Proposed mechanism of the reaction between sulfoximines and iodonium ylides.

Scheme 19

Rhodium-catalyzed strategy for the synthesis of polycyclic 1,2-benzothiazines.

Scheme 20

Ru(II)-catalyzed C–H functionalization strategy of sulfoximines for the enantioselective synthesis of 1,2-benzothiazines.

Scheme 21

Proposed mechanism of Ru-catalyzed enantioselective synthesis of 1,2-benzothiazines.

Scheme 22

Rh(III)-catalyzed C–H functionalization of sulfoximines to prepare dihydrobenzo thiadiazine 1-oxide derivatives.

Scheme 23

Proposed mechanism of C–H functionalization of sulfoximines and annulation with benzyl azides.

Scheme 24

Ir(III)-catalyzed amidation/cyclization for the C–H activation of sulfoximines with N-alkoxyamides to synthesize the corresponding thiadiazine 1-oxides.

Scheme 25

Proposed catalytic cycle.

Scheme 26

Rh(III)-catalyzed method to obtain benzothiadiazine-1-oxides using 1,4,2-dioxazol-5-ones.

Scheme 27

Proposed mechanism.

Scheme 28

Co(III)-catalyzed enantioselective C–N bond formation of cyclic sulfoximines.

Scheme 29

Ru(II)/chiral-carboxylic-acid-catalyzed enantioselectivity synthesis of seven-membered cyclic sulfoximines.

Scheme 30

The synthesis of 1, 2-benzothiazines in the Rh(Ⅲ) catalytic system using alkynyl silanes.

Scheme 31

Proposed mechanism of annulation of sulfoximines and alkynyl silanes in the Rh catalytic system.

Scheme 32

Tandem Rh(Ⅲ)-catalyzed C–H activation of sulfoximines to furnish furanone-fused 1,2-benzothiazines derivatives.

Scheme 33

Pd(II)-catalyzed C–H functionalization strategy for the preparation of dibenzothiazines.

Scheme 34

Proposed mechanism of Pd-catalyzed annulation of sulfoximines with arynes.

Scheme 35

Metal-free method for the intramolecular C–N coupling to form benzothiazines.

Scheme 36

Tandem C–H activation and C–N coupling of sulfoximines to form iodo-thiazines.

Scheme 37

Metal-free tandem amination/bromination method for the synthesis of bromobenzothiazines.

Scheme 38

DBH-promoted strategy for the cyclization of sulfoximines.

Scheme 39

Pd/norbornene-catalyzed coupling reaction for the synthesis of fused polycyclic sulfoximines.