The upsurge interesti nt he development of efficient methodologies for the constructiono fn itrogen-containing frameworks via the use of expedient reagents have been creating ar enaissance in contemporary organic chemistry.I nt his perspective, tertbutyl nitrite (TBN) is an emerging building block. Due to its uniques tructuralf eatures, it shows differential reactivity under different reaction conditions. These diverse reactivities have resulted in the construction of ad iverse array of complex N-containing molecules. The primary objective of the presentr eview is to bring the latest findings of TBN in terms of its applications in reactions (oxidation, diazotization, nitrosation, nitration, oximation, N-synthon, and miscellaneous reactions) into the limelight.F or simplicity and brevity,r eactions in each section are explained with the mechanism of formation and selected examples are given.Scheme1.Differential reactivity of TBN. 4455 MinireviewScheme4.Visible-light-promoted synthesis of selenide ethers.Scheme5.Proposed mechanism for visible-light-promoted synthesis of selenide ethers.Scheme6.TBN-mediated synthesis of selenide ethers.Scheme7.Metal-free synthesis of 4-carbonylquinolines.Scheme8.Proposed mechanism for synthesis of 4-carbonylquinolines.Scheme9.TBN-mediated demethylative borylation of methylarenes.Scheme10. Plausible mechanism for demethylative borylation of methylarenes.Scheme11. Trifluoromethylation of various aromatic amine substrates.Scheme12. Copper-catalyzed isoperfluoropropylation of anilines.Scheme13. Plausible mechanism for Cu-catalyzed isoperfluoropropylation of anilines.Scheme14. TBN-mediateddiazotizative allylation of aromatic amines.Scheme15. Oxidativecyanomethylationo fa lkenes via CÀHb ond activation.Scheme16. TBN-mediatedand Cu-catalyzedsynthesis of thioether.

The one-pot synthetic strategies for 2,4,6-triarylnicotinonitriles and 2,5-diaryl-1H-pyrrole-3-carbonitriles have been accomplished via a Pd-catalyzed coupling of arylboronic acid with 2-(3-oxo-1,3-diarylpropyl)­malononitrile and 2-(2-oxo-2-arylethyl)­malononitrile, respectively, under mild reaction conditions, followed by intramolecular cyclization of an intermediate formed after the regeneration of the catalyst under acidic reaction conditions. The cascade reactions proceed in 1,2-dichloroethane solvent under visible-light irradiation, and the active catalyst is generated in situ in the presence of catalytic amounts of Pd­(OAc)2 and 2,2′-bipyridine. The active Pd catalyst undergoes photoexcitation by the virtue of metal-to-ligand charge transfer (MLCT), and subsequent redox trans-metalation occurs with arylboronic acid, thus obviating the necessity of any exogenous photosensitizer. The targeted products, composed of a new C–C, a C–N, a CN, and two new CC bonds, were isolated in good yields.

A visible-light-induced synthesis of N-hydroxybenzimidoyl cyanides from aromatic terminal alkenes is achieved by using Eosin Y as an organic photoredox catalyst. The process goes via a radical pathway with successive incorporation of two nitrogen atoms, one each from tert-butyl nitrite and ammonium acetate. The final product is achieved by the concomitant installation of an oxime and a nitrile group. DFT calculation supports a biradical pathway and all the proposed steps. A few useful synthetic transformations of N-hydroxybenzimidoyl cyanide are also illustrated.

An electrochemical amidation of benzoyl hydrazine/ carbazate and primary/secondary amine as coupling partners via concomitant cleavage and formation of C(sp 2 )−N bonds has been achieved. This methodology proceeds under metal-free and exogenous oxidant-free conditions producing N 2 and H 2 as byproducts. Mechanistic studies reveal the in situ generations of both acyl and N-centered radicals from benzoyl hydrazines and amines. The utility of this protocol is demonstrated through a largescale, and synthesis of bezafibrate, a hyperlipidemic drug.

The in situ generated o-alkynylthioureas obtain by reacting 2-(phenylethynyl)anilines and aryl isothiocynates undergo efficient cascade cyclization in the presence of AgCO to form indoloquinolines under microwave heating. The present tandem process allows the generation of a variety of indolo[2,3-b]quinolines derivatives in good to moderate yields with a wide functional group tolerance.

The nitrile or cyano (-CN) group is one of the most appreciated and effective functional groups in organic synthesis having a polar unsaturated C-N triple bond. Despite sufficient stability and...

tert-Butyl nitrite (TBN) mediated synthesis of 3-aryl-1,2,4-oxadiazol-5­(4H)-ones has been accomplished using terminal aryl alkenes via a biradical reaction intermediate. Three consecutive sp2 C–H bond functionalizations of styrenes afforded 3-phenyl-1,2,4-oxadiazol-5­(4H)-ones via the formation of new CN, CO, C–O, and two C–N bonds. Both of the N atoms originate from TBN, while the carbonyl oxygen is from the water (moisture) the other oxygen from the NO part of the TBN.

A visible-light-mediated concomitant C3 oxidation and C2 amination of indoles has been achieved at room temperature using an Ir (III) photocatalyst. This reaction proceeds without an isatin intermediate via the attack of a singlet oxygen at the C3 position followed by C2 amination leading to difunctionalization of indoles.