1,2‐Thiazines: One‐Pot Syntheses Utilizing Mono and Diaza Analogs of Sulfones

Abstract

A one-pot Michael addition/cyclization/condensation reaction sequence for the regioselective synthesis of 1,2-thiazines, starting from propargyl ketones and NH-sulfoximines or NH-sulfondiimines, has been developed. Under mild and operationally simple reaction conditions previously unprecedented 1,2-thiazine 1-imide and 1-oxide derivatives are formed in good to excellent yields. The products represent heterocyclic building blocks, readily modifiable by a regioselective C-H bond functionalization, classical cross-coupling reactions, and deprotection.

Tandem Reactions of Ynones: via Conjugate Addition of Nitrogen‐, Carbon‐, Oxygen‐, Boron‐, Silicon‐, Phosphorus‐, and Sulfur‐Containing Nucleophiles

“…The RNH–Nu strategy could be used in the reaction of ynones with secondary amines. When treated with RNH–Nu, ynones underwent a Michael addition first [Eq. (16‐1)].…”

“…As reported by Bolm and co‐workers in 2016, exposure of ynones to NH‐sulfoximines (or NH‐sulfonediimines) enabled the one‐pot construction of heterocyclic building blocks [Eqs. (17‐1) and (17‐2)].…”

Accessing Enantiopure Endocyclic Sulfoximines Through Catalytic Cycloisomerization of Oxygenated Propargyl‐Sulfinamides

“…Despite this growing interest, only a few methods are currently available for the synthesis of enantiopure sulfoximines, relying mainly on resolution of racemic mixtures, [6] the stereospecific imidation of enantioenriched sulfoxides [7] and oxidation of enan-tioenriched sulfimides, [8] or imidative kinetic resolution of racemic sulfoxides. [10] The preparation of 5-membered cyclic sulfoximines remains less explored [11] and their synthesis in enantiopure form is limited to rather rare examples. [10] The preparation of 5-membered cyclic sulfoximines remains less explored [11] and their synthesis in enantiopure form is limited to rather rare examples.…”

“…[9] Owing to the interest of heterocyclic compounds in medicinal chemistry, different strategies to access cyclic sulfoximines have also been developed, especially for the synthesis of 6membered and benzo-fused derivatives. [10] The preparation of 5-membered cyclic sulfoximines remains less explored [11] and their synthesis in enantiopure form is limited to rather rare examples. [11c,e,f,h] Following our studies on the synthesis of enantiopure oxygenated propargyl-sulfinamides, [12] we envisioned that these unique substrates could provide an easy access to unprecedented enantiopure 5-membered endocyclic sulfoximines, through a simple cycloisomerization reaction, capitalizing on the activation of the electron-rich oxygenated triple bond by p-acidic transition metal catalysts.…”

An Efficient Synthesis of 1,3-Benzothiadiazin-4(3H)-one 2-Oxides: Novel Anthranilic Acid Derivatives

“…Our interest in sulfonimidamides has focused on developing methods to constrain the N-S-N linkage in a ring system; 7,9,10 such compounds can be viewed as restricted conformations of open-chain sulfonimidamides, and with the correct design elements can be expected to offer improved ligand efficiency and biological activity.…”