Mechanistic Investigation of the Staudinger Ligation
摘要:
The Staudinger ligation of azides and phosphines has found widespread use in the field of chemical biology, but the mechanism of the transformation has not been characterized in detail. In this work, we undertook a mechanistic study of the Staudinger ligation with a focus on factors that affect reaction kinetics and on the identification of intermediates. The Staudinger ligation with alkyl azides was second-order overall and proceeded more rapidly in polar, protic solvents. Hammett analyses demonstrated that electron-donating substituents on the phosphine accelerate the overall reaction. The electronic and steric properties of the ester had no significant impact on the overall rate but did affect product ratios. Finally, the structure of an intermediate that accumulates under anhydrous conditions was identified. These findings establish a platform for optimizing the Staudinger ligation for expanded use in biological applications.
Mechanistic Investigation of the Staudinger Ligation
摘要:
The Staudinger ligation of azides and phosphines has found widespread use in the field of chemical biology, but the mechanism of the transformation has not been characterized in detail. In this work, we undertook a mechanistic study of the Staudinger ligation with a focus on factors that affect reaction kinetics and on the identification of intermediates. The Staudinger ligation with alkyl azides was second-order overall and proceeded more rapidly in polar, protic solvents. Hammett analyses demonstrated that electron-donating substituents on the phosphine accelerate the overall reaction. The electronic and steric properties of the ester had no significant impact on the overall rate but did affect product ratios. Finally, the structure of an intermediate that accumulates under anhydrous conditions was identified. These findings establish a platform for optimizing the Staudinger ligation for expanded use in biological applications.
Latent fluorescent compounds, comprising a fluorescent molecule with one or more blocking groups attached and optionally one or more urea-containing groups are provided. The urea-containing group can be used to further attach one or more molecules of interest, such as proteins, peptides or nucleic acids. The blocking group(s) is released from the latent fluorescent compound by reaction with a trigger, forming the fluorescent molecule which can be detected. Also provided herein are methods of using latent fluorescent compounds to detect triggers.
US7534902B2
申请人:——
公开号:US7534902B2
公开(公告)日:2009-05-19
US8034928B2
申请人:——
公开号:US8034928B2
公开(公告)日:2011-10-11
Mechanistic Investigation of the Staudinger Ligation
作者:Fiona L. Lin、Helen M. Hoyt、Herman van Halbeek、Robert G. Bergman、Carolyn R. Bertozzi
DOI:10.1021/ja044461m
日期:2005.3.1
The Staudinger ligation of azides and phosphines has found widespread use in the field of chemical biology, but the mechanism of the transformation has not been characterized in detail. In this work, we undertook a mechanistic study of the Staudinger ligation with a focus on factors that affect reaction kinetics and on the identification of intermediates. The Staudinger ligation with alkyl azides was second-order overall and proceeded more rapidly in polar, protic solvents. Hammett analyses demonstrated that electron-donating substituents on the phosphine accelerate the overall reaction. The electronic and steric properties of the ester had no significant impact on the overall rate but did affect product ratios. Finally, the structure of an intermediate that accumulates under anhydrous conditions was identified. These findings establish a platform for optimizing the Staudinger ligation for expanded use in biological applications.