A series of donor−acceptor−acceptor (D−A− A) and donor−acceptor−donor (D−A−D) systems based on a pyrimidine π-spacer with various substituents at the C-2 position has been successfully prepared. The synthesis involved site-selective palladium cross-coupling reactions of chloropyrimidines with triorganoindium reagents and proceed in good yields and with atom economy. 4-(N,N-Diphenylamino)phenyl was chosen as the donor group and thien-2-yl dicyanovinylene as the acceptor one. The optical, vibrational, electrochemical, and density functional theory (DFT) calculations of these molecular systems were analyzed, and experimental values show the important role of the substituents at the C-2 position of the pyrimidine with stronger electron accepting ability, absorption in a wide range of UV/vis, acceptable fluorescence lifetime, and effective intramolecular charge transfer (ICT) properties. The ICT was observed in both series by the bathochromic shift on increasing the polarity of the solvent. In addition, DFT calculations found lower lowest unoccupied molecular orbitals of D−A−A molecules that suggest good electron ejection and transportation, being good properties for their application in various organic optoelectronic devices.

Triorganoindium reagents (R3In, R = aryl, heteroaryl, alkynyl) react selectively under palladium catalysis with N-benzyl-2,4,5-triiodoimidazole to afford the C-2 monocoupling products. The reaction proceeds efficiently for a variety of aryl- and heteroarylindium reagents with the transfer of all three organic groups attached to the metal. The coupling products can be used in a subsequent two-fold cross-coupling to give trisubstituted imidazoles in good yields. This approach was employed to synthesize neurodazine and analogues in good yields.

4,6-Disubstituted-2-(4-morpholinyl)pyrimidines, an important class of bioactive compounds, have been synthesized from 4,6-dichloro-2-(4-morpholinyl)pyrimidine by selective and sequential palladium-catalyzed cross-coupling reactions using triorganoindium reagents. This methodology, being efficient and versatile, allowed the synthesis of a variety of non-symmetrical pyrimidines functionalized at C-4 and C-6 positions.

The preparation of ferrocenylindium species and palladium‐catalyzed cross‐coupling reactions for the synthesis of monosubstituted and planar chiral 1,2‐disubstituted ferrocenes is described. Triferrocenylindium reagents (Fc3In) are efficiently prepared in a one‐pot procedure from ferrocenes by lithiation and transmetallation to indium using InCl3. The palladium‐catalyzed cross‐coupling reactions of Fc3In (40 mol%) with a variety of organic electrophiles (aryl, heteroaryl, benzyl, alkenyl and acyl halides) in THF at 80 °C overnight provided a wide variety of monosubstituted ferrocenes in good to excellent yields. This methodology allowed the stereoselective synthesis of planar chiral 2‐aryl‐1‐oxazolylferrocenes and 2‐aryl‐1‐sulfinylferrocenes, which are of interest in asymmetric catalysis.magnified image

The cross-coupling sequence is used for preparation of neurodazine (VI) and analogs. -(PEREZ-CAAVEIRO, C.; PEREZ SESTELO, J.; MARTINEZ*, M. M.; SARANDESES, L. A.; J. Org. Chem. 79 (2014) 20, 9586-9593, http://dx.