Rhodium(III)‐Catalyzed Selective CH Cyanation of Indolines and Indoles with an Easily Accessible Cyano Source

Abstract

The rhodium‐catalyzed selective cyanation of CH bonds of indolines and indoles with N‐cyano‐N‐phenyl‐para‐methylbenzenesulfonamide is described. This protocol offers a facile access to C‐7 cyanated indolines and C‐2 cyanated indoles with high site selectivity and excellent functional group tolerance.magnified image

Transition‐Metal‐Catalyzed Cyanation by Using an Electrophilic Cyanating Agent, N‐Cyano‐N‐phenyl‐p‐toluenesulfonamide (NCTS)

“…[22] Both N-carbonyl and carbamoylindolines workedw ell in this transformation, therebya ffording the corresponding C7-cyanated indolines in moderate-to-good yields. [22] Both N-carbonyl and carbamoylindolines workedw ell in this transformation, therebya ffording the corresponding C7-cyanated indolines in moderate-to-good yields.…”

Rhodium‐Catalyzed C(sp2)‐ or C(sp3)−H Bond Functionalization Assisted by Removable Directing Groups

“…Va rious reports on amide-or ap yrimidyl-directed Rh IIIcatalyzed C1-functionalizations,s uch as heteroarylation, [226] alkylation, [227] cyanation, [221,229] allylation, [228] and alkenylation, [230] have been reported ( Table 2). Va rious reports on amide-or ap yrimidyl-directed Rh IIIcatalyzed C1-functionalizations,s uch as heteroarylation, [226] alkylation, [227] cyanation, [221,229] allylation, [228] and alkenylation, [230] have been reported ( Table 2).…”

“…In fact, by following this strategy,avariety of C7-functionalizations of indoline have been addressed in the past few years,i ncluding alkenylation, [231] alkylation, [227,232] allylation, [228,233] and cyanation [229] ( Table 3). In fact, by following this strategy,avariety of C7-functionalizations of indoline have been addressed in the past few years,i ncluding alkenylation, [231] alkylation, [227,232] allylation, [228,233] and cyanation [229] ( Table 3).…”

“…Similar to indole derivatives,c arbazole was also selectively functionalized by introducing ad irecting group on the NH moiety.The proximity of the C1ÀHand the incorporated directing group controls the selectivity of the reaction. Va rious reports on amide-or ap yrimidyl-directed Rh IIIcatalyzed C1-functionalizations,s uch as heteroarylation, [226] alkylation, [227] cyanation, [221,229] allylation, [228] and alkenylation, [230] have been reported ( Table 2).…”

“…Thelarge functional group tolerance contributes to the importance of these findings.T omore clearly demonstrate the utility of the alkenylation reaction, the N,N-diisopropylcarbamoyl directing group was removed smoothly by treatment with an aqueous 50 %s olution of NaOH in ethanol to provide the desired indazole derivative 205 in high yield (Scheme 63). [226] (heteroarylation) 2014, Yang and Zhou [227] (alkylation) 2014, Xu [221] (cyanation) 2015, Kim [228] (allylation) 2015, Kim [199] (cyanation) 2016, Tanand Ma [230] (alkenylation) [231] (alkenylation) 2014, Yang and Zhou [227] (alkylation) 2015, Kim [233] (allylation) 2015, Kim [228] (allylation) 2015, Kim [229] (cyanation) 2016, Li [232] (alkylation) Scheme 62. Rh III -catalyzed C7-alkenylation of indazole derivatives with alkenes.…”