Dearomative Indole Bisfunctionalization via a Diastereoselective Palladium-Catalyzed Arylcyanation

Abstract

The first Pd-catalyzed dearomative indole bisfunctionalization via a diastereoselective arylcyanation is reported. This method facilitates the formation of diverse indoline scaffolds bearing congested stereocenters with high levels of diastereoselectivity. This also represents the first example of a cyanation mechanism involving a 2° benzylic Pd(II) intermediate.

Reductive dearomative arylcarboxylation of indoles with CO2 via visible-light photoredox catalysis

“…Dearomative functionalization of indoles are particularly interesting to generate important indolines 15,16 . Although many methods have been developed in this field [17][18][19][20][21][22][23][24][25] , the dearomative reductive coupling of indoles with two electrophiles is still challenging due to the stability of carbon-carbon double bond within aromaticity and thus slow migratory insertion rate. In 2017, Qin et al realized an elegant Nicatalyzed asymmetric reductive hydroarylation of carbon-carbon double bond in indoles with water as proton source ( Fig.…”

Dearomative 1,4-difunctionalization of naphthalenes via palladium-catalyzed tandem Heck/Suzuki coupling reaction

“…1a) [10][11][12][13][14][15][16] . On the other hand, as disclosed recently by the groups of Lautens [17][18][19][20] , Liang 21 , Yin 22,23 , Zhou 24 , Wu 25 , and us [26][27][28][29][30] , the application of endocyclic C=C bonds of heteroarenes as non-classic olefins has enabled a number of efficient dearomative difunctionalization reactions of indoles and furans with Pd-or Ni-catalyst 31 . This dearomatizing strategy undoubtedly expands the scope of olefin difunctionalization reaction to arenes and constitutes an important method for the synthesis of valuable three-dimensional molecules from simple planar aromatics [32][33][34][35][36][37][38] .…”

Quadruple C-H activation coupled to hydrofunctionalization and C-H silylation/borylation enabled by weakly coordinated palladium catalyst

“…To reach this goal, subsequent β-H elimination should be interrupted; it is a typical side reaction in many cascade and 1,2-difunctionalization transformations, and is extremely hard to avoid because of favorable kinetics 12 . A typical solution for avoiding β-H elimination is to introduce a blocking group at the β-carbon position [13][14][15][16] . Other alternatives include adding a hydrogen source to afford a reductive Heck product [17][18][19][20][21][22][23][24] , introducing norbornene derivatives in the Catellani reaction [25][26][27][28] , producing a π-allyl/benzyl intermediate [29][30][31] , and oxidizing the Pd (II) to Pd(IV) to create practicable methods [32][33][34][35][36][37] .…”

“…2a). Various 2′-OHacetophenone substrates (R 1 ) bearing an electron-donating group, a halogen group, or a multiply substituted group all reacted smoothly to provide the corresponding products in high yields (5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19). Next, we investigated the effect of the substituent R 2 .…”