Intramolecular cyclization of A catalyzed by IDA in benzene or THF yields two γ-lactams through C-alkylation and one δ-and one 7-membered lactam by O-alkylation.
Binary mixtures of alcohols(ethyl,n-butyl and n-amyl)with several aprotic sol- vents,such as acetone,dioxane,THF,DMSO and DMF have been studied systematically by ~1H,^(13)C,^(15)N and ^(17)O NMR measurements.The conce...Binary mixtures of alcohols(ethyl,n-butyl and n-amyl)with several aprotic sol- vents,such as acetone,dioxane,THF,DMSO and DMF have been studied systematically by ~1H,^(13)C,^(15)N and ^(17)O NMR measurements.The concentration dependence of chemical shift of the solvent was used to evaluate equilibrium constants of the complexation of alcohols with the solvents.A relationship between the proton shift of alcohol uncombined with the solvent and its concentration was found,and the fraction of unassociated hydroxyl groups was thus quantitatively described.The effect of solvent on self association and complexation of the alcohol is discussed on the basis of the electron donicity of the solvents.展开更多
Herein,phloroglucinol tristearate(PhgTS)was used to study the crystallization process due to its unique symmetric structure containing a benzene ring and three aliphatic chains.Spherulites of crystallized PhgTS from f...Herein,phloroglucinol tristearate(PhgTS)was used to study the crystallization process due to its unique symmetric structure containing a benzene ring and three aliphatic chains.Spherulites of crystallized PhgTS from four solvents under diverse conditions were analyzed in detail and their formation process was studied.Maltese cross is shown by PhgTS spherulites obtained from aprotic solvents via polarized optical microscopy.In comparison,no Maltese cross can be observed from branch-like crystals formed from protic solvents.Independent on the micro-scaled morphology,lamellae were found to be the basic blocks constructing both PhgTS spherulites and branch-like crystals,which were formed predominantly by stacked PhgTS molecules.Although differential characters of the solvents did not affect the formation of lamellas,the solvents played a crucial role in the formation of self-assembled microscaled morphologies.In particular,the morphologies of spherulites were strongly affected by the concentration of PhgTS solutions,surrounding tempera-ture and evaporation rate of solvents.Generally,a higher concentration of PhgTS led to more homogeneous spherulites,a lower evaporation rate resulted in more compact spherulites,and a higher surounding temperature generated preferentially more ring-banded spherulites of PhgTS.展开更多
文摘Intramolecular cyclization of A catalyzed by IDA in benzene or THF yields two γ-lactams through C-alkylation and one δ-and one 7-membered lactam by O-alkylation.
文摘Binary mixtures of alcohols(ethyl,n-butyl and n-amyl)with several aprotic sol- vents,such as acetone,dioxane,THF,DMSO and DMF have been studied systematically by ~1H,^(13)C,^(15)N and ^(17)O NMR measurements.The concentration dependence of chemical shift of the solvent was used to evaluate equilibrium constants of the complexation of alcohols with the solvents.A relationship between the proton shift of alcohol uncombined with the solvent and its concentration was found,and the fraction of unassociated hydroxyl groups was thus quantitatively described.The effect of solvent on self association and complexation of the alcohol is discussed on the basis of the electron donicity of the solvents.
基金Y.Y.thanks the China Scholarship Council(CSC)for financial support.K.Z.thanks Georg-August-University of Goettingen for the Anschubfinanzierung(Funding for the Promotion of Young Academics of University of Goettingen)and Fonds der Chemischen Industrie(FCI)for the financial support.The authors declare no conflicts of interest.
文摘Herein,phloroglucinol tristearate(PhgTS)was used to study the crystallization process due to its unique symmetric structure containing a benzene ring and three aliphatic chains.Spherulites of crystallized PhgTS from four solvents under diverse conditions were analyzed in detail and their formation process was studied.Maltese cross is shown by PhgTS spherulites obtained from aprotic solvents via polarized optical microscopy.In comparison,no Maltese cross can be observed from branch-like crystals formed from protic solvents.Independent on the micro-scaled morphology,lamellae were found to be the basic blocks constructing both PhgTS spherulites and branch-like crystals,which were formed predominantly by stacked PhgTS molecules.Although differential characters of the solvents did not affect the formation of lamellas,the solvents played a crucial role in the formation of self-assembled microscaled morphologies.In particular,the morphologies of spherulites were strongly affected by the concentration of PhgTS solutions,surrounding tempera-ture and evaporation rate of solvents.Generally,a higher concentration of PhgTS led to more homogeneous spherulites,a lower evaporation rate resulted in more compact spherulites,and a higher surounding temperature generated preferentially more ring-banded spherulites of PhgTS.
