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It is found that the reaction of dimethyl 2-phenylcyclopropane-1,1-dicarboxylate with 2 equivalents each of aromatic aldehydes and TaCl5 in 1,2-dichloroethane at 23 °C for 24 h after hydrolysis gives substituted 4-phenyl-3,4-dihydronaphtalene-2,2(1H)-dicarboxylates in good yield. This represents a new type of reactions between 2-arylcyclopropane-1,1-dicarboxylates and aromatic aldehydes, yielding chlorinated tetrahydronaphthalenes with a cis arrangement of the aryl and chlorine substituents in the cyclohexene moiety. A plausible reaction mechanism is proposed. [ABSTRACT FROM AUTHOR]

The reaction of alkyl‐ and aryl‐substituted carboxylic acids with primary and secondary amines under the action of 0.2 equiv. TaCl5 leads to selective formation of carboxylic acid amides of various structures. TaCl5‐catalyzed formation of amides was demonstrated to proceed equally selectively both in toluene and methylene chloride, hexane, diethyl ether and 1,4‐dioxane solutions. [ABSTRACT FROM AUTHOR]

The present article details a novel approach for introducing strained 2,3-dimethylenebicyclo[2,2,0]hexane structures into the C60 fullerene molecule, based on the reaction of C60 with substituted propargylamines, promoted by the Ti(Oi-Pr)4 and EtMgBr system. The theoretical LUMO energies of the strained C60 derivatives calculated at the PBEPBE/6-311G(d,p) level of theory are from −3.93 to −4.09 eV, which indicates that these compounds seem to be promising as electron-acceptor materials for bulk heterojunction organic solar cells. [ABSTRACT FROM AUTHOR]

Titanium(IV) isopropoxide and ethylmagnesium bromide catalyzed reaction of 2-alkynylamines with Et2Zn, followed by deuterolysis/ hydrolysis and iodinolysis, affords substituted (Z)-pent-2-en-2,5- d2-1-amines, (Z)-pent-2-en-1-amines (65-88%), and substituted (Z)- 2,5-diiodopent-2-en-1-amines (55-63%). It is suggested that the reaction proceeds through the formation of cyclic organotitanium derivatives. The reaction between 1-alkynylphosphines and Et2Zn in the presence of catalytic amounts of Ti(O-iPr)4 and EtMgBr leads to trisubstituted 1-alkenylphosphine oxides with high regioselectivity and stereoselectivity. [ABSTRACT FROM AUTHOR]

The unusual transformation of N-isoalkyl-substituted propargylamines into alkenylamines under the action of Cp2ZrCl2 and organoaluminum compounds (Me3Al, EtAlCl2) has been observed. The proposed mechanism, involving the N-isoalkyl-substituted propargylamine undergoing zirconocene-initiated intramolecular hydride transfer was supported by B3LYP/6-31G(d)/LanL2DZ calculations. [ABSTRACT FROM AUTHOR]

Substituted alkylidenecyclopropanes reacted with 5 equivalents each of Me3Al and CH2I2 at room temperature in hexane to give 1-mono- and 1,1-disubstituted spiro[2.2]pentanes in high yields. Surprisingly, the same reaction with substituted alkylidenecyclopropanes in CH2Cl2 afforded exclusively 1,1-disubstituted spiro[2.3]hexanes. The transformation of 1,1-diphenylspiro[2.2]pentane into 1,1-diphenylspiro[2.3]hexane was studied with the use of CD2I2 and a plausible mechanism was suggested. The reaction of substituted alkylidenecyclobutanes with the Me3Al/CH2I2 reagent in CH2Cl2 gave only 1,1-disubstituted spiro[2.3]hexanes. [ABSTRACT FROM AUTHOR]