Click and Release: A Chemical Strategy toward Developing Gasotransmitter Prodrugs by Using an Intramolecular Diels-Alder Reaction
作者:Xingyue Ji、Cheng Zhou、Kaili Ji、Robert E. Aghoghovbia、Zhixiang Pan、Vayou Chittavong、Bowen Ke、Binghe Wang
DOI:10.1002/anie.201608732
日期:2016.12.19
derivatization. By taking advantage of an intramolecular Diels–Alder reaction, we have developed a prodrugstrategy for preparations of organic CO prodrugs that are stable during synthesis and storage, and yet readily release CO with tunable release rates under near physiological conditions. The effectiveness of the CO prodrug system in delivering a sufficient quantity of CO for possible therapeutic applications
pi ligands such as olefins and alkynes bind intramolecularly to the metal atom in d(0) complexes of the large alkaline earths (Ae) calcium and strontium supported by fluoroalkoxo ligands with dangling unsaturated C=C or C C bonds, and having the amide N(SiMe2H)(2)(-) as the coligand. These O-bridged dinuclear complexes are further stabilized by secondary C-F-->Ae and beta-Si-H center dot center dot center dot Ae interactions. In a set of structurally related Ca-olefin complexes, the strength of these interactions gradually increases as the coordination of the olefin onto Ca2+ becomes weaker (from eta(2)-coordinated to eta(1) to fully dissociated) upon increasing steric congestion, thus ensuring that over-whelming electronic depletion does not occur at calcium. NMR data imply that the olefins are metal-bound in [D-8]toluene solutions. The Ae center dot center dot center dot C-pi, C-F-->Ae, and beta-Si-H center dot center dot center dot Ae noncovalent interactions are also strong in the parent Ae-alkyne complexes, the first examples of non-acetylide Ae-alkynes compounds. Calcium-arene complexes could not be made, as the aromatic tether did not bind to the metal atom. Instead, a trinuclear complex with noninteracting C6H5 groups was obtained. It exhibits exceptionally strong C-F-->Ca and beta-Si-H center dot center dot center dot Ca interactions. NMR data indicate that the congeneric calcium-allene complex can be made, but it spontaneously isomerizes toward the more stable Ca-alkyne via an unusual 1,3-hydride shift intramolecular process.
Click and Release: SO<sub>2</sub> Prodrugs with Tunable Release Rates
作者:Xingyue Ji、Eman M. El-labbad、Kaili Ji、Deena S. Lasheen、Rabah A. T. Serya、Khaled A. Abouzid、Binghe Wang
DOI:10.1021/acs.orglett.6b03805
日期:2017.2.17
Employing an intramolecular cycloaddition reaction, we have developed a series of SO2 prodrugs with tunable release rates with half-lives ranging from minutes to days.
Organic CO Prodrugs: Structure-CO-Release Rate Relationship Studies
作者:Zhixiang Pan、Vayou Chittavong、Wei Li、Jun Zhang、Kaili Ji、Mengyuan Zhu、Xingyue Ji、Binghe Wang
DOI:10.1002/chem.201700936
日期:2017.7.21
monoxide (CO) is an endogenously produced gasotransmitter in mammals, and may have signaling roles in bacteria as well. It has many recognized therapeutic effects. A significant challenge in this field is the development of pharmaceutically acceptable forms of CO delivery with controllable and tunable release rates. Herein, the structure–release ratestudies of the first class of organicCOprodrugs that
Strained, Stable 2-Aza-1-Phosphabicyclo[n.1.0]alkane and -alkene Fe(CO)4 Complexes with Dynamic Phosphinidene Behavior
作者:Mark L. G. Borst、Niels van der Riet、Renske H. Lemmens、Franciscus J. J. de Kanter、Marius Schakel、Andreas W. Ehlers、Allison M. Mills、Martin Lutz、Anthony L. Spek、Koop Lammertsma
DOI:10.1002/chem.200401249
日期:2005.6.6
remarkably stable, as illustrated by the X-ray crystal structure for 7 b (n=3), yet all readily undergo retroaddition to react with phenylacetylene. Shuttling of the phosphinidene iron complex between two equivalent C=C groups is demonstrated for a 1-butene-substituted 2-aza-1-phosphabicyclo[3.1.0]hexane by selective (1)H NMR magnetization transfer from the phosphirane protons to the olefinic protons. Even