Transition-Metal-Free Stereospecific Oxidative Annulative Coupling of Indolines with Aziridines

Synthesis of cinnamoyl tethered indoline derivatives with anti-inflammatory and antioxidant activities

Aimed to improve the anti-inflammatory activities of natural antioxidant caffeic acid phenethyl ester, the thirty derivatives of cinnamoyl tethered indoline were synthesized. The structure-activity relationship indicated that the fragments of catechol and 5-Cl-indolinyl were beneficial for the higher dual-activities of antioxidant and anti-inflammation. The most potent compound 4b suppressed the secretions of inflammatory cytokines IL-6 and TNF-α, inhibited inducible nitric oxide synthase (iNOS) expression, upregulated the antioxidant gene HO-1 expression and antioxidant enzyme SOD level, and inhibited oxidative stress marker MDA level. Besides, 4b and its acetate prodrug 4'b could effectively attenuate paw edema more than CAPE. In regard to anti-inflammatory mechanism, 4b suppressed the NF-κB activation associated with phosphorylation of p65 subunit and degradation of IκBα. In summary, this study provided a new anti-inflammatory derivative 4b which was worthy of further research.

Sc(OTf)3-Catalyzed Domino C-C/C-N Bond Formation of Aziridines with Quinones via Radical Pathway

Sc(III)-catalyzed domino C-C and C-N bond formation of N-sulfonyl aziridines with quinones has been accomplished to furnish functionalized indolines at a moderate temperature. The umpolung reactivity of aziridines, radical pathway, mild reaction conditions, substrate scope, and coupling of drug molecules in a postsynthetic application are the important practical features.

Iodine-promoted synthesis of CF3-substituted dihydroimidazobenzimidazole and CF3-dihydroimidazoindole via C-N bond formation

The iodine-promoted cyclization of various N-(2-CF3-2-NHTs)ethylbenzimidazoles and N-(2-CF3-2-NHTs)ethylindoles proceeded smoothly and efficiently under mild basic conditions. This reaction did not require transition metals and afforded the corresponding CF3-dihydroimidazobenzimidazoles and CF3-dihydroimidazoindoles in 85-93% and 42-82% yields, respectively.

Regioselective and stereospecific synthesis of functionalized 3,4-dihydro-2H-1,4-thiazines by catalyst-free [3 + 3] annulation of pyridinium 1,4-zwitterionic thiolates and aziridines

An efficient route to 3,4-dihydro-2H-1,4-thiazines was developed though [3 + 3] annulation of pyridinium 1,4-zwitterionic thiolates and aziridines under catalyst-free conditions.

Photo-Induced N-N Coupling of o-Nitrobenzyl Alcohols and Indolines To Give N-Aryl-1-amino Indoles

A novel method to synthesize N-aryl-1-amino indoles was established by the photoinduced N-N coupling reaction. This protocol is by treatment of o-nitrobenzyl alcohols and indolines in the presence of TEAI and acetic acid with a 24 W ultraviolet (UV) light-emitting diode (LED) (385-405 nm) irradiation. The products bearing an aldehyde group can be further transformed to fluorescent probes based on Rhodamine 6G derivative 11, which shows a high specificity and sensitivity for Fe³⁺.

Photoinduced triiodide-mediated [3 + 2] cycloaddition of N-tosyl aziridines and alkenes

A photoinduced triiodide-mediated [3 + 2] cycloaddition of N-Ts aziridines and alkenes is described herein. This operationally simple protocol enables regioselective access to a wide range of substituted pyrrolidines under mild-free conditions.