Nickel‐Catalyzed Regio‐ and Enantioselective Annulation Reactions of 1,2,3,4‐Benzothiatriazine‐1,1(2H)‐dioxides with Allenes

Abstract

Extrusion of N2: 1,2,3,4‐Benzothiatriazine‐1,1(2H)‐dioxides reacted with allenes in the presence of a nickel(0)/(R)‐quinap complex to produce a variety of substituted 3,4‐dihydro‐1,2‐benzothiazine‐1,1(2H)‐dioxides in a regio‐ and enantioselective fashion. An intermediate nickelacycle was generated through denitrogenative activation of the triazo moiety which allowed the intermolecular incorporation of an allene group. quinap=1‐(2‐diphenylphosphino‐1‐naphthyl)isoquinoline.

Übergangsmetallkatalysierte denitrogenierende Transanellierungen: Umwandlung von Triazolen in andere heterocyclische Systeme

“…Murakami et al berichteten 2010 [43] über die nickelkatalysierte enantioselektive Transanellierungsreaktion des 1,2,3,4-Benzothiatriazin-1,2(2H)-dioxids 64 mit monosubstituierten Allenen unter Bildung der 1,2,3,4-Benzothiazin-1,1(2H)-dioxid-Derivate 65 und 66. Es wurde angenommen, dass diese Reaktion mit einer oxidativen Addition von Ni 0 an die N-N-Bindung beginnt und durch Eliminierung eines Stickstoffmoleküls das fünfgliedrige Intermediat 67 gebildet wird.…”

“…[43] Allene, die Siloxy-, Benzyloxy-und N-Phthalimidoylgruppen an den Alkylketten aufwiesen, waren ebenfalls gute Reaktanten, obwohl etwas niedrigere Enantioselektivitäten beobachtet wurden (Schema 30).…”

Regioselective Synthesis of 1,2-Benzothiazine 1,1-Dioxide Derivatives by Intramolecular Heck Cyclization

“…1). Murakami et al 15 developed a nickel-catalyzed regioand enantioselective annulation reaction between 1,2,3,4-benzothiatriazine 1,1(2H)-dioxide and allene for access to 1,2-benzothiazine 1,1-dioxide derivatives with exocyclic double bond (Scheme 1, eq. 2).…”

Decarbonylative CC Bond‐Forming Reactions of Saccharins by Nickel Catalysis: Homocoupling and Cycloaddition

“…[20] However, step-economical, [21] metal-catalyzed cycloaddition approaches to benzosultams are comparatively less well-studied. [22] Screening of reaction conditions for the cycloaddition of saccharin 1 a with alkyne 3 a was conducted and the identified optimal conditions afforded the desired benzosultam 4 a in 85 % yield in the presence of 50 mol % of nickel (0) catalyst [Eq. (2)].…”