Pyrrolo pyrrole-1,3

Diketo-pyrrolo-pyrrol, pigment for plastics, 7 367t... 

The homo- and heterochiral self-association of lH-l,6a-dihydropirrolo[2,3-b] pyrrole derivatives has been studied using density functional theory (DFT) (B3LYP/ 6-31+G ) and ab initio (MP2/6-311+G ) methods [26]. The selected pyrrolo-pyrrole structure (Scheme 3.16) has a unique disposition of theNH group situated in cis to the substituent in position 6a. This simplifies the study, reducing the potential number of conformations, and also maximizes the interaction of the 6a position X groups in the homochiral complexes, as they are forced to point each other. 

For the intermolecular proton transfer in the dimers, similar behavior and structures as in the previously described pyrrolo-pyrroles are found, being the nonconcerted TS the true states, with only one imaginary frequency, and Cs symmetry. The proton transfer energy barriers of the dimers range between 59... 

Zhang, X., Richter, L.J., Delongchamp, D.M., KUne, R.J., Hammond, M.R., Mcculloch, I., Heeney, M., Ashraf, R.S., Smith, J.N., Anthopoulos, X.D., Schroeder, B., Geerts,Y.H., Fischer, D.A., Toney, M.E, 2011. Molecular packing of high-mobility diketo pyrrolo-pyrrole polymer semiconductors with branched alkyl side chains. J. Am. Chem. Soc. 133,15073-15084. 

Wienk, M.M., Turbiez, M., Gilot, J., Janseen, R.A.J. Narrow-bandgap diketo-pyrrolo-pyrrole polymer solar cells the effect of processing on the performance. Adv. Mater. 20, 2556-2560 (2008)... 

Pyrrolo[3,2-6]pyrrole, N,N -dimethyl-UV spectra, 4, 1044 Pyrrolo[3,2-6]pyrrole, octahydro-synthesis, 4, 1081 Pyrrolopyrroles H NMR, 4, 1041 occurrence, 4, 1042 reactivity, 4, 1049 synthesis, 4, 1068 Pyrrolo[2,3-6]pyrroles ionization potentials, 4, 1046 synthesis, 4, 293, 1070 Pyrrolo[3,2-6]pyrroles synthesis, 6, 1009 Pyrrolo[3,2-6]pyrroles, dihydrosynthesis, 4, 1081 Pyrrolo[3,4-c]pyrroles applications, 4, 1083 Pyrroloquinolines... 

On saponification l-(2-methoxycarbonylphenyl)pyrrole yields l-(2-carboxyphenyl)pyrrole, m.p. 106-107°, which on reaction with polyphosphoric acid at 70° is cyclized to 9-keto-9H-pyrrolo-(l,2-a)indole in 28-32% yield. Through the choice of the appropriate amine and acetal components, the substituted l-(2-meth-oxycarbonylphenyl)pyrroles become readily available intermediates in the preparation of a variety of derivatives of the pyrrolo( 1,2-a) indole ring system. 

Pyrrolo[l,2-a]azepin-9-one (12), which in acid solution exists as the cation 13, is prepared by thermal cyclization of ( , )-4-(dimethylaniino)buta-l,3-dienyl pyrrol-2-yl ketone (ll)7. 

Pyrrolo[l,2-a]azepin-5-one (11), prepared by cyclization of methyl 5-(pyrrol-2-yl)penta-2,4-dienoate (10) with sodium hydride in toluene, in trifluoroacetic acid solution forms the diatropic 5-hydroxypyrrolo[1,2-a]azepinium ion 12.216 6-Methyl-5//-pyrrolo[l,2-tf]azepin-5-one(mp41 -43 C), formed in low yield (20%) by the action of [(ethoxycarbonyl)methylene]triphenylphos-phorane on 4-(pyrrol-2-yl)but-3-en-2-one, behaves similarly. 

The Mitsunobu reaction was applied to the synthesis of pyrrolo[l,2-d [, 2,4]triazines from pyrrole derivative 71. Thus reduction of 71 gave alcohol 72, which on treatment with diethylazodicarboxylate and triphenyl phosphine gave 74 via the open chain intermediate 73. Hydrolysis of 74 gave 75 (84AG517) (Scheme 18). 

Pyrrolo[l,2-fl]thieno[2,3-c]pyrazine (186) brominated mainly in the fused pyrrole ring. Only the third bromine atom introduced substituted the thiophene /3-position (86JHC17). 

Langer and coworkers constructed diverse O- and N-heterocydic scaffolds, such as y-alkylidene-a-hydroxybutenolides and pyrrolo[3,2-b]pyrrol-2,5-diones, exploiting the well-established cyclization strategy of bisnucleophiles with oxalic acid derivatives [163], while Stockman s research group reported in this context on a novel oxime formation/Michael addition providing the structural core of the alkaloid perhydrohistrionicotoxin [164]. 

For example, McNab and coworkers have discovered that flash-vacuum pyrolysis (FVP) (1000 °C, 0.01 Torr) of pyrrole 10-114 led to the formation of pyrrolo[2,l-a]isoindol-5-one 10-117 in 79% (Scheme 10.29) [44]. The transformation is proposed to proceed via an initial 1,5-aryl shift to give intermediate 10-115, which then undergoes an elimination of methanol. Finally, electrocydization of the ketene 10-116 results in the formation of 10-117. 

The pyrrolo[2,3-c/]pyrimidine anticancer agent is prepared utilizing, as a key sequence, Michael condensation of 2,6-diamino-4(.37/)-pyrimidinone with nitroalkenes, followed by the Nef reaction that leads to the annulated pyrrole ring (Eq. 10.67).98... 

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