Rhodium(III)‐Catalyzed Synthesis of N‐(2‐Acetoxyalkyl)isoquinolones from Oxazolines and Alkynes through C−N Bond Formation and Ring‐Opening

Abstract

An atom-economic approach for the synthesis of N-(2-acetoxyalkyl)isoquinolones from oxazolines and alkynes through rhodium(III)-catalyzed auto-tandem reactions involving CÀH bond functionalization/CÀN bond formation/ring opening/nucleophilic substitution is described. This protocol features high regioselectivity, tolerance of various functional groups, and retention of absolute configuration of chirality. Exploration of the reaction mechanism reveals that Cu(OAc) 2 not only acts as the oxidant, but also provides acetate to promote the reaction in this process.

Isoquinolone Syntheses by Annulation Protocols

“…[46], with N-iminopyridinium ylides (Scheme (c)) [47]. However, with the use of AgNTf 2 as co-catalyst, the reactions of 2-aryloxazolines with alkynes afford N-substituted isoquinolones (Scheme 10 (d)) [48]. In the presence of KOAc, [Cp*Co(CO)I 2 ]/AgOAc-catalyzed [4 + 2] annulation of Nchlorobenzamides with alkynes in TFE occurs at room temperature with selective cleavage of C-H/N-Cl bonds (Scheme 11) [49].…”

“…As shown in Scheme 10, with the use of [Cp*RhCl 2 ] 2 as catalyst, the annulations of alkynes with benzoyl hydrazines (Scheme 10 (a)) [45], with 1,4,2-dioxazol-5-ones occur at room temperature (Scheme 10 (b))[46], with N-iminopyridinium ylides (Scheme (c))[47]. However, with the use of AgNTf 2 as co-catalyst, the reactions of 2-aryloxazolines with alkynes afford N-substituted isoquinolones (Scheme 10 (d))[48].…”

Gold‐Catalyzed Amination Reactions: Progress and Prospects

“…C−N bond‐forming reaction is an effective way to introduce nitrogen atom in organic compounds [9,10] . These organonitrogen compounds play a significant role in catalysis, [11,12] medicinal chemistry, [13] atom economic reactions, [14] and natural product synthesis [15] . Earlier, aryl amines were synthesized via the hydrogenation of nitro group using platinum, copper, or nickel [16] …”

Palladium-catalyzed regio- and stereoselective synthesis of aryl and 3-indolyl-substituted 4-methylene-3,4-dihydroisoquinolin-1(2H)-ones

“…Moreover, these heterocycles can be used as 5-HT3 antagonists [9], rho kinase inhibitors [10], thymidylate synthetase inhibitors [11], PARP-1 inhibitors [12], melatonin MT 1 and MT 2 receptor agonist [13], and fascin-targeted antimetastatic agents [14]. Fittingly, the development of efficient strategies for their construction and peripheral functionalization represents still an active research area aimed to achieve structural diversity [15][16][17][18].…”