Search

Herein we developed a useful method for the preparation of the desired sulfilimines with readily available sulfonamides as nitrogen sources and iodobenzene as the catalyst. The reaction proceeds via the in-situ produced hypervalent iodine from catalytic simple iodobenzene under electrooxidation conditions. This oxidative coupling strategy can be employed for a wide range of aromatic sulfide and sulfonamide. The obtained sulfilimines could be easily transformed to biologically important N H free sulfoximines in good yields. [Display omitted] Sulfilimines, the aza-analogs of sulfoxides, are valuable building blocks in organic synthesis and serve as important functional groups in medicinal chemistry. Herein we reported an efficient and environmentally friendly method of preparing sulfilimines from readily available thioether and sulfonamide as substrate. The reaction proceeds via the in-situ produced hypervalent iodine from catalytic simple iodobenzene under electrooxidation conditions. A series of sulfilimines were obtained in moderate to good yields. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Easy to control. • New sulfenylation agent without odor. • No oxidant required. Abstract Using sulfinamides as a new reagent for preparation of asymmetrical thioethers has been developed under metal-free conditions. The reactions proceeded smoothly without the use of stinky thiophenol, highly toxic sulfonyl chloride or oxidant. Such a simple, efficient transformation provides an attractive approach to various diaryl sulfides in good to excellent yields. [ABSTRACT FROM AUTHOR]

Traditional preparation of sulfenamides require the use of low oxidation state of sulfur reagent such as RSCl, (RS) 2 or RSH, which are toxic, odorous and difficult to deal with due to the harsh reaction conditions. Here high oxidation state of sulfur reagent—aliphatic sulfinamide, were used for preparation of sulfenamide in one step efficiently. Different aromatic amines with all sorts of functional groups, especially amino groups and hydroxyl groups, were transformed to the corresponding sulfenamides in moderate yields, which was difficult to obtain with previous methods. [ABSTRACT FROM AUTHOR]

We have developed a highly efficient and practical strategy for the kinetic resolution of indoline derivatives, involving a chiral Brønsted acid-catalyzed iminium ion formation and asymmetric transfer hydrogenation cascade process. The kinetic resolution allows the synthesis of 2-substituted N -benzylindolines in good yields with moderate to excellent enantioselectivities. [ABSTRACT FROM AUTHOR]

An exceptionally simple and environmentally friendly methodology has been developed for directly functionalizing the benzylic C–H bond of the poly-substituted pyridines with aromatic imines. Simple Brønsted acid catalysts including salicylic acid and TsOH were successfully employed. Different types of poly-substituted pyridines could be efficiently obtained with moderate yields. Traditional ways to such types of pyridines involved the aromatization of the corresponding Hantzsch 1,4-dihydropyridines, while this method greatly simplified the synthetic procedures. [ABSTRACT FROM AUTHOR]

Abstract: Solvent effect upon asymmetric photosensitization has been investigated in the enantiodifferentiating photoisomerization of cyclooctene(1Z), sensitized by benzoate modified β-cyclodextrin derivatives bearing nitrogen, oxygen or sulfur substituents. The enantiomeric excess (ee) and E/Z ratio of reaction products were susceptible to the concentration of methanol in the aqueous solution, which could switch to the chirality of product unprecedentedly. Further investigation indicated that the conformation of the modified CDs in aqueous methanol solutions with 1Z were highly sensitive to both the substituent(s) on benzoate moiety of the modified CDs and the concentration of methanol. Solvent content represents a new versatile tool to efficiently manipulate the asymmetric photochemical reactions, in which the chirality of products can be switched by simply changing the methanol content of reaction solvent rather than synthesizing the antipodal sensitizers. [Copyright &y& Elsevier]

Abstract: The asymmetric direct aldol reactions of a wide scope of aromatic aldehydes, with unmodified ketones in the presence of 1mol% of organocatalyst prepared from (2R,3R)-diethyl 2-amino-3-hydroxysuccinate and trans-4-hydroxy-l-proline, were performed in water, affording aldol products in high yields with excellent diastereoselectivities of up to >99:1 and enantioselectivities of up to 98%. [Copyright &y& Elsevier]

• Developing biomimetic alloxan-catalyzed intramolecular redox reaction with O 2. • The process underwent two oxidations under mild and metal-free reaction conditions. • The environmentally benign molecular oxygen as the only sacrificial reagent. • One-pot atom-economic synthesis of various sulfinyl-functionalized benzimidazoles. Given the necessity of sacrificial reductants in various biomimetic aerobic oxygenations, alloxan-catalyzed aerobic redox system for one-pot atom-economic synthesis of sulfinyl-functionalized benzimidazoles was developed by ingeniously binding both the substrate sulfide and sacrificial reductant. This mild and transition-metal-free protocol undergoes two oxidations without additional sacrificial reagents, except for the environmentally benign molecular oxygen. [ABSTRACT FROM AUTHOR]