Recent Advances in Highly Selective Applications of Nitroso Compounds

Abstract

Abstract:Over the past few years, substantial progress has been achieved in the development of nitroso-related organic chemistry. Annulations of nitroso compounds with other π-conjugated systems, especially the notable hetero Diels-Aldertype reaction, have drawn much interest from organic chemists, because of their regioselective, enantioselective and highly efficient advantages. In addition, the N-nitroso moiety can also be employed as powerful and transformable directing group in specific C-H direct functionalization reactions. Herein, we summarized the versatile applications of nitroso compounds as useful building blocks in the selective synthesis of diverse molecules in recent years.

Gold‐catalyzed [4+2] Annulations of Dienes with Nitrosoarenes as 4 π Donors: Nitroso‐Povarov Reactions

“…The isolation of the O-addition product 5ainfers the intermediacy of the nitrosonium B.However, 5a is unlikely to be the main [a] [1] = 0.05 M. The isolation of the O-addition product 5ainfers the intermediacy of the nitrosonium B.However, 5a is unlikely to be the main [a] [1] = 0.05 M.…”

“…We assessed these new [4+ +2] annulations using various vinylallenes.T he results are summarized in Table 2and show two distinct annulations,a sc ontrolled by the allenyl C1 substituents,t hat is,R 1 = aryl versus alkyl. Thep roducts 3 correspond to the annulations with the tetrasubstituted alkenes of the dienes 1' ',w hereas 3' ' arises from the trisubstituted alkenes.W et ested the [4+ +2] annulations on various C1-aryl-substituted vinylallenes (1b-e;X= Me,OMe,Brand Cl), giving the compounds 3b-e in satisfactory yields (entries [1][2][3][4]. These annulations were also operable with their 3-and 2-substituted phenyl derivatives 1f-h (X = Me, Cl, R 1 = 2-MeC 6 H 4 ), affording the desired products 3f-h in 59-79 %yields (entries 5-7).…”

“…Nitrosoarenes are very versatile and undergo metal-catalyzed cycloadditions [1,2] with p-bond motifs including dienes, [2] alkynes, [3] and allenes. [4] These cycloadditions are accessible to valuable 1,n-aminoalcohols through reductive cleavage of the weak N À Obonds of cycloadducts.Catalytic [4+ +2] cycloadditions of dienes with nitrosoarenes represent one of the most successful reactions in metal catalysis because of their facile access to 1,4-aminoalcohols in high diastereo-and enantiomeric purity [Scheme 1, Eq.…”

“…(1)]. [1,2] We are aware of no examples wherein nitrosoarenes serve as 4 p donors in catalytic annulations,a lthough [4+ +2] cycloadditions between transient nitrosoalkenes and electron-rich alkenes are well known [Eq. (1)].…”

“…[a][1] = 0.2 M. [b] Product yields were obtained after purification from asilica column. [c] These yields were estimated based on the cyclopentadienes 1' '.L= P(t-Bu) 2 (o-biphenyl).…”