An Efficient Method for the Programmed Synthesis of Multifunctional Diketopyrrolopyrroles

Abstract

An ew,t ransformative methodology for the preparation of diketopyrrolopyrroles from aldehydes,p rimary amines,n itriles,a nd diethyl oxalacetate has been developed. It is nowpossible to prepare diketopyrrolopyrroles bearing an ordered arrangement of three different substituents from abundant and commercially available materials,a llowing the independent regulation of all desired physicochemical properties.F or the first time very electron-rich (carbazol-3-yl, dimethylaminophenyl, pyrrolo[3,2-b]pyrrolyl), and sterically hindered substituents (naphthalen-1-yl, quinolin-4-yl, acridin-9-yl, imidazo[1,5-a]pyridin-1-yl, 2-bromophenyl etc.)c an be appended to the diketopyrrolopyrrole core by condensation of an appropriate nitrile with ap yrrolidin-2-one intermediate. Even greater synthetic possibilities are related to the fact that such demanding substituents as 4-dimethylaminophenyl, indol-3-yl, and 2-methoxyphenyl can be incorporated from aldehyde precursors,b ypassing problems with the nitriles reactivity.

A Convenient Synthesis of Diketopyrrolopyrrole Dyes

“…The DPP bicyclic system is usually generated from the reaction of aryl nitriles with diethyl (or diisopropyl) succinate in the presence of a strong base, and frequently the expected symmetrical DPP derivatives are obtained in low to moderate yields [ 44 ]. Other approaches, developed for the synthesis of non-symmetrical DPP derivatives, require precursors not easily available or long synthetic routes [ 1 , 45 , 46 , 47 ]. An attractive approach to new DPPs involves the modification of adequately functionalized DPP derivatives.…”

The Synthesis and Photophysical Properties of Weakly Coupled Diketopyrrolopyrroles

“…Looking for chromophores, which possess the suitable architecture for probing via weakening of their intramolecular electronic coupling, we focused on diketopyrrolopyrrole (DPP) derivatives ( Figure 1 ) [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ]. These donor–acceptor cross-conjugated dyes with DPP cores are characterized by straightforward synthesis [ 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ], almost a unity emission quantum yield [ 21 ], large two-photon absorption cross-section [ 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ], and broad utility in organic optoelectronics [ 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 , …”

“…Looking for chromophores, which possess the suitable architecture for probing via weakening of their intramolecular electronic coupling, we focused on diketopyrrolopyrrole (DPP) derivatives (Figure 1) [21][22][23][24][25][26][27][28][29]. These donor-acceptor cross-conjugated dyes with DPP cores are characterized by straightforward synthesis [30][31][32][33][34][35][36][37], almost a unity emission quantum yield [21], large two-photon absorption cross-section [38][39][40][41][42][43][44][45], and broad utility in organic optoelectronics . Depending on the dihedral angle between C-aryl substituents and the core, the absorption of DPPs ranges from 500 to 600 nm [21].…”

Synthesis of densely substituted pyridine derivatives from nitriles by a non-classical [4+2] cycloaddition/1,5-hydrogen shift strategy

“…cyano, carbonyl, ester groups) carbons, though some elegant work has been made by using transition metal catalysts. [65][66][67][68][69][70][71][72][73][74][75][76][77][78][79][80][81] The di culty level of these reactions increases drastically when substrates with weakly acidic C(sp 3 )-H (especially for pKa > 40 in DMSO) bond are utilized, and the methods in this eld are rarely developed. 82 To address these challenges, a non-classical [4 + 2] cycloaddition along with 1,5-hydrogen shift strategy is proposed (Fig.…”