123344-13-8

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• 75-89-8 2,2,2-trifluoroethanol 
• 1033571-87-7 4,4'-bis(morpholino)benzhydryl acetate 
• 123344-06-9 4-[4-(4-Morpholin-4-yl-benzylidene)-cyclohexa-2,5-dienylidene]-morpholin-4-ium 
• 115043-23-7 bis[4-(morpholin-4-yl)phenyl] ketone 
• 345-92-6 4,4'-Difluorobenzophenone 

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• 1033571-87-7 4,4'-bis(morpholino)benzhydryl acetate 
• 1220284-26-3 C₂₇H₃₄N₂O₃ 

Relevant academic research and scientific papers

How constant are Ritchie's constant selectivity relationships ? A general reactivity scale for n-, π-, and σ-nucleophiles

The kinetics of 82 reactions of benzhydrylium ions (Ar2CH+) with n-nucleophiles has been determined at 20 °C. Evaluation by the equation log k = s(N + E) delivered the reactivity parameters N and s for 15 n-nucleophiles (water, hydroxide, amines, etc.). All nucleophiles except water (s = 0.89) and -SCH2CO2- (s = 0.43) have closely similar slope parameters (0.52 + + log k0 yields a statistically validated set of N+ parameters for Ritchie-type nucleophiles and log k0 parameters for benzhydrylium ions. The N and s parameters of the n-nucleophiles derived from their reactions with benzhydrylium ions were combined with literature data for the reactions of these nucleophiles with other carbocations to yield electrophilicity parameters E for tritylium, tropylium, and xanthylium ions. While the E parameters for tropylium and xanthylium ions appear to be generally applicable, it is demonstrated that the E parameters of tritylium ions can be used to predict reactivities toward n-nucleophiles as well as hydride transfer rate constants but not rates for the reactions of tritylium ions with π-nucleophiles. It is now possible to merge the large data sets determined by Ritchie and others with our kinetic data and present a nucleophilicity scale comprising n- (e.g., amines), π- (e.g., alkenes and arenes), and σ-nucleophiles (e.g., hydrides).

Synthesis, Structure, and Properties of Amino-Substituted Benzhydrylium Ions – A Link between Ordinary Carbocations and Neutral Electrophiles

Optimized synthetic procedures for the straightforward access to eleven amino-substituted diarylmethylium tetrafluoroborates are described. These benzhydrylium ions cover a range of seven orders of magnitude in electrophilicity and provide a link between ordinary carbocations and neutral electrophiles. Five of these highly stabilized benzhydrylium tetrafluoroborates were characterized by single-crystal X-ray crystallography. While the experimentally determined bond lengths and angles in the solid state perfectly agree with those calculated by DFT methods for the gas phase and aqueous solution, crystal packing accounts for large differences in the twist angles of the aryl groups found in the solid state as compared to calculated structures.

Asymmetric SN 1 α-Alkylation of cyclic ketones catalyzed by functionalized chiral ionic liquid (FCIL) organocatalysts

Ionic liquid works better: The first intermolecular asymmetric α-alkylation of cyclic ketones was realized by using functionalized chiral ionic liquids as catalysts. The reaction proceeded with good to excellent yields and high ee. Highly stereoselective desymmetrization of 4-substituted cyclohexanones with >99:1 d.r. and up to 87 % ee were achieved by using this protocol. (Chemical Equation Representation).

"Carbocation watching" in solvolysis reactions

(Figure Presented) The missing link between conventional SN1 reactions and the chemistry of stable carbocations has been found. When water is added to the colorless solution of the covalent compound Ar2CH-OAc (Ar = morpholinophenyl)

Solvent Nucleophilicity

The rates of the reactions of benzhydrylium ions (diarylcarbenium ions) with solvent mixtures of variable composition (water/acetonitrile, methanol/acetonitrile, ethanol/acetonitrile, ethanol/water, and trifluoroethanol/water) have been determined photometrically by conventional UV-vis spectroscopy, stopped-flow methods, and laser flash techniques. It has been shown that the first-order rate constants follow the previously published relationship log k(20°C) = s(N+E), where E is an empirical electrophilicity parameter, N is an empirical nucleophilicity parameter, and s is a nucleophile-specific slope parameter. From plots of log k versus E of the benzhydrylium ions are derived the solvent nucleophilicity parameters s and N, the latter of which are designated as N1 to emphasize that their use in the quoted correlation equation gives rise to first-order rate constants. A linear correlation between N1 and Kevill's solvent nucleophilicity NT based on S-methyldibenzothiophenium ions is reported, which allows one to interconvert the two sets of data. Because the N1 values are directly comparable to the previously reported nucleophilicity parameters N for π-systems (www.cup.uni-muenchen.de/oc/mayr/), the systematic design of Friedel-Crafts reactions with solvolytically generated carbocations becomes possible.

SN1 reactions with inverse rate profiles

Carbocations may accumulate during solvolysis reactions! The fact that fast ionization followed by slow trapping of the carbocation R+ is a characteristic pattern of many solvolysis reactions requires that the generally accepted energy profiles of these reactions be revised.