A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxi...

A new approach to the assembly and photochemical disassembly of molecular hosts is developed. It is based on photoinduced fragmentation in hydroxyalkyl dithianes and utilizes a novel spiro-bis-dithiane as a photolabile molecular tether to link two formylated macromolecular blocks, e.g., formyl calixarenes or formyl dibenzocrown ethers. A key feature of this molecular system is that after an ass...

The crystal structures of the title compounds, C19H19NO and C31H34N2O, were determined as part of an experiment in an undergraduate teaching laboratory that demonstrates the relationship between mol-ecular structure and function. 1',3',3'-Tri-methyl-spiro-[chromene-2,2'-indoline] is both a photoswitch and thermochromic mol-ecule. Students synthesized it and a bis-indoline adduct and compared th...

The N-heterocyclic carbene catalyzed annulation of benzofuran-2,3-diones and enals via homoenolate intermediates is described. The reaction provided a direct and efficient method for the synthesis of spiro-bis-lactones. The ketone-carbonyl group annulated products and the ester-carbonyl group annulated products can be obtained as major products with good yields by convenient catalyst regulation...

First attempts are described to prepare a precursor for an all-carbon analog of indigo, the tetracyclic triene 4. Starting from indan-2-one (9) the α-methylene ketone 13 was prepared. Upon subjecting this compound to a McMurry coupling reaction, it dimerized to the bis-indene derivative 17, rather than providing the tetramethyl derivative of 4, the hydrocarbon 14. In a second approach, indan-1-...

The synthesis of aromatic poly(ether imide)s containing spirobifluorene units in the polymer backbone is described. 2,29-Bis(3,4-dicarboxyphenoxy)-9,99-spirobifluorene dianhydride, which was used as a new monomer, was synthesized with 2,29-dihydroxy-9,99-spirobifluorene as the starting material. In the spiro-segment, the rings of the connected bifluorene were orthogonally arranged. This bis(eth...

The reactions of carbodiimides with the iron arylborylene complex [Fe=BDur(CO)3(PMe3)] (Dur=2,3,5,6-Me4C6H) and bis(borylene) [Fe{=BDur}{=BN(SiMe3)2}(CO)3] yield a wide variety temperature-dependent products, including known FeBNC novel FeBNB metallacycles, complexes N-heterocyclic boracarbene spiro-boracarbene ligands unique 1,3,2,4-diazadiborolyl pianostool complex, characterized by NMR spect...

This paper describes an efficient and regioselective method for the synthesis of novel fluorinated spiro-heterocycles in excellent yield by cascade [5+1] double Michael addition reactions. The compounds 7,11-bis(4-fluorophenyl)-2,4-dimethyl- 2,4-diazaspiro[5.5] undecane-1,3,5,9-tetraone (3a) and 2,4-dimethyl-7,11-bis (4-(trifluoromethyl)phenyl)-2,4-diazaspiro[5.5]undecane-1,3,5,9-tetraone (3b) ...

Despite considerable development in performance, both poor operational stability and high costs associated with hole conductors such as 2,2′,7,7′-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9′-spirobifluorene (spiro-OMeTAD) Poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine (PTAA) of perovskite solar cells (PSCs) need to be addressed by the research community. Here, two nonspiro transporting materials...