Sulfoximines: A Reusable Directing Group for Chemo‐ and Regioselective ortho CH Oxidation of Arenes

Abstract

Sulfoximines direct: a new protocol for the chemo- and regioselective ortho C-H acetoxylation of arenes in N-benzoylated sulfoximines is reported. The sulfoximine directing group is easily detached from the C-H oxidation product through acid-promoted hydrolysis, isolated, and reused. The meta-substituted phenols are synthesized following this strategy and the stereointegrity of the sulfoximine is preserved in this transformation. C(sp(3))-H acetoxylation of the methyl group is also demonstrated.

Synthesis of chiral sulfoximine-based thioureas and their application in asymmetric organocatalysis

“…Further exemplary contributions come from medicinal chemistry where sulfoximines show potential as enzyme inhibitors [10–14], and from materials science where they were evaluated as functional building blocks [15]. In addition, sulfoximines are most present in synthetic organic chemistry for various reasons and recent findings include their use as fluoromethylation reagents, as fluorophores or as directing groups [16–19]. Two quality characteristics make them particularly attractive for asymmetric synthesis: 1) The stereogenic sulfur atom which is stable towards many reaction conditions, and 2) the ease of functionalization at the adjacent nitrogen and carbon atoms which allows a great structural diversity of the sulfoximine motif.…”

Preparation of Enantiomerically Pure Perfluorobutanesulfinamide and Its Application to the Asymmetric Synthesis of α-Amino Acids

“…Tetrahydrofuran and diethyl ether were purified by passage through activated alumina using a solvent purification system. [Cp*RhCl 2 ] 2 , 28 AgB(C 6 F 5 ) 4 , 29 benzoylpyrrolidine, 30 azobenzenes, 31 sulfoximine, 32 N -aryl-1 H -pyrazoles, 33 and 1-benzyl-4-phenyl-1 H -1,2,3-triazoles 34 were synthesized according to published procedures. 1,2-Dichloroethane (DCE) was deoxygenated by sparging with nitrogen gas followed by storage over activated 3 Å molecular sieves for 48 h prior to use.…”

Ruthenium- and palladium-catalyzed consecutive coupling and cyclization of aromatic sulfoximines with phenylboronic acids: an efficient route to dibenzothiazines

“…In all these reactions, >99% ee ratios were observed. Further, (S)-(-)-S-methyl-S-phenylsulfoximine (7b) underwent ortho arylation with aromatic boronic acids 2a, 2b and 2e in the presence of ruthenium catalyst, providing chiral ortho arylated 45 phenyl sulfoximines 7ba-be in 67%, 65% and 61% yields, respectively, with >99% ee ratios. Further, 7ba-be were converted into chiral dibenzothiazines 8e-g in the presence of Pd(OAc) 2 in 72%, 82% and 83% yields, respectively.…”

“…Herein, we report the synthesis of tricyclic dibenzothiazines by a ruthenium-catalyzed ortho arylation of phenyl sulfoximines 45 with aromatic boronic acids followed by intramolecular cyclization in the presence of palladium catalyst in the consecutive two steps (eq. 2).…”

“…Table 1 summarizes the results of these reactions. Treatment of 4-phenyl substituted phenylboronic acid 45 (2b) with 1a provided ortho bis arylated product 5ab in 72% yield (entry 1). Electron rich 4-methoxyphenyl boronic acid (2c) reacts smoothly with 1a, yielding the corresponding product 5ac in 66% yield (entry 2).…”