1,8-Bis(dimethylethyleneguanidino)naphthalene: Tailoring the Basicity of Bisguanidine “Proton Sponges” by Experiment and Theory
摘要:
1,8-Bis(dimethylethyleneguanidino)naphthalene (DMEGN), the second example of a peralkyl guanidine "proton sponge" based on the 1,8-naphthalene backbone, was prepared and fully characterized. The crystal structure analysis of monoprotonated DMEGN reveals an unsymmetrical intramolecular hydrogen bridge. A decrease in the basicity with respect to the noncyclic parent 1,8-bis(tetramethylguanidino)naphthalene was found. Nevertheless, a new proton sponge provides a new crossbar in the ladder of highly basic neutral organic compounds. A detailed theoretical study of DMEGN and related cyclic guanidines explains this surprising experimental result. Homodesmotic reactions reveal that the intramolecular hydrogen bond contributes effectively 10 kcal/mol to proton affinity of DMEGN.
1,8-Bis(dimethylethyleneguanidino)naphthalene: Tailoring the Basicity of Bisguanidine “Proton Sponges” by Experiment and Theory
摘要:
1,8-Bis(dimethylethyleneguanidino)naphthalene (DMEGN), the second example of a peralkyl guanidine "proton sponge" based on the 1,8-naphthalene backbone, was prepared and fully characterized. The crystal structure analysis of monoprotonated DMEGN reveals an unsymmetrical intramolecular hydrogen bridge. A decrease in the basicity with respect to the noncyclic parent 1,8-bis(tetramethylguanidino)naphthalene was found. Nevertheless, a new proton sponge provides a new crossbar in the ladder of highly basic neutral organic compounds. A detailed theoretical study of DMEGN and related cyclic guanidines explains this surprising experimental result. Homodesmotic reactions reveal that the intramolecular hydrogen bond contributes effectively 10 kcal/mol to proton affinity of DMEGN.
Composition de défrisage des cheveux comprenant au moins une multiguanidine hors hydroxyde
申请人:L'ORÉAL
公开号:EP1723946A1
公开(公告)日:2006-11-22
L'invention a pour objet une composition cosmétique de défrisage des fibres kératiniques prête à l'emploi, le milieu cosmétiquement acceptable, contenant, en tant qu'agent actif de défrisage, une multiguanidine n'appartenant pas à la famille des hydroxydes. Elle vise également un kit contenant des compartiments à mettre en contact pour former la composition prête à l'emploi, ainsi qu'un procédé mettant en oeuvre cette composition.
Hair shaping composition comprising at least one polyguanidine other than hydroxide
申请人:Malle Gerard
公开号:US20060269498A1
公开(公告)日:2006-11-30
Disclosed herein is a ready-to-use cosmetic composition for shaping keratin fibers, comprising, in a cosmetically acceptable medium, as active agent for shaping, a polyguanidine not belonging to the hydroxide family. Also disclosed herein is a kit comprising at least two compartments to be brought into contact to form the ready-to-use composition. Further disclosed herein is a method for shaping keratin fibers comprising applying this composition to the keratin fibers.
1,8-Bis(dimethylethyleneguanidino)naphthalene: Tailoring the Basicity of Bisguanidine “Proton Sponges” by Experiment and Theory
作者:Volker Raab、Klaus Harms、Jörg Sundermeyer、Borislav Kovačević、Zvonimir B. Maksić
DOI:10.1021/jo034906+
日期:2003.11.1
1,8-Bis(dimethylethyleneguanidino)naphthalene (DMEGN), the second example of a peralkyl guanidine "proton sponge" based on the 1,8-naphthalene backbone, was prepared and fully characterized. The crystal structure analysis of monoprotonated DMEGN reveals an unsymmetrical intramolecular hydrogen bridge. A decrease in the basicity with respect to the noncyclic parent 1,8-bis(tetramethylguanidino)naphthalene was found. Nevertheless, a new proton sponge provides a new crossbar in the ladder of highly basic neutral organic compounds. A detailed theoretical study of DMEGN and related cyclic guanidines explains this surprising experimental result. Homodesmotic reactions reveal that the intramolecular hydrogen bond contributes effectively 10 kcal/mol to proton affinity of DMEGN.