Site-Selective Nickel-Catalyzed Hydrogen Isotope Exchange in <i>N</i>-Heterocycles and Its Application to the Tritiation of Pharmaceuticals
作者:Haifeng Yang、Cayetana Zarate、W. Neil Palmer、Nelo Rivera、David Hesk、Paul J. Chirik
DOI:10.1021/acscatal.8b03717
日期:2018.11.2
advantages over existing methods, including: (i) high HIE activity at low D2 or T2 pressure; (ii) tolerance of functional groups, including aryl chlorides, alcohols, secondary amides, and sulfones; (iii) activity with nitrogen-rich molecules such as the chemotherapeutic imatinib; and (iv) the ability to promote HIE in sterically hindered positions generally inaccessible with other transition metal catalysts
Selective Ru(0)-Catalyzed Deuteration of Electron-Rich and Electron-Poor Nitrogen-Containing Heterocycles
作者:Birgit Gröll、Michael Schnürch、Marko D. Mihovilovic
DOI:10.1021/jo300219v
日期:2012.5.4
A highly selective Ru3(CO)12-catalyzed deuteration method using t-BuOD as deuterium source is reported. Electron-rich and electron-poor N-heteroarenes such as indoles, azaindoles, deazapurines, benzimidazole, quinolines, isoquinolines, and pyridines were efficiently deuterated at specific positions with high selectivity; in most cases, deuterium incorporation was close to the theoretically possible
Deuterodecarboxylation, the replacement of a COOD group by a D atom, proceeds with high specificity in good yields for a series of pyridine-2-carboxylic acids. Isomeric pyridine-carboxylic acids require higher temperatures to achieve decarboxylation and give multiply deuterated products. Positions adjacent to the ring N are especially favored in the H—D exchange reactions. The role of ylid intermediates
Surface site distributions by solid-state multinuclear NMR spectroscopy. Pyridine binding to .gamma.-alumina by nitrogen-15 and deuterium NMR
作者:Paul D. Majors、Paul D. Ellis
DOI:10.1021/ja00240a008
日期:1987.3
octahedral Lewis acid sites are determined as a function of surface preparation conditions, and the results are used with a simple surface preparation model to calculate the relative contribution of the various low index lattice planes to the composition of the surface. /sup 2/H NMR line-shape studies of pyridine-..cap alpha..,..cap alpha..'-d/sub 2/ on ..gamma..-alumina indicate a heterogeneous distribution
Bimetallic H<sub>2</sub> Addition and Intramolecular Caryl–H Activation Mediated by an Iron–Zinc Hydride
作者:Rui Sun、Yang Jiang、Hao-Ran Chen、Xuebin Jiang、Yu-Chen Cao、Shengfa Ye、Rong-Zhen Liao、Chen-Ho Tung、Wenguang Wang
DOI:10.1021/acs.inorgchem.4c00454
日期:2024.4.1
Cp*Fe(1,2-Cy2PC6H4)HZnEt (3) undergoes reversible intramolecular Caryl-H reductive elimination through coupling of the cyclometalated phosphinoaryl ligand and the hydride, giving rise to a formal Fe(0)–Zn(II) species. Addition of CO intercepts this equilibrium, affording Cp*(Cy2PPh)(CO)Fe-ZnEt that features a dative Fe–Zn bond. Significantly, this system achieves bimetallic H2 addition, as demonstrated by
异核Fe(μ-H)Zn氢化物Cp*Fe(1,2-Cy 2 PC 6 H 4 )HZnEt ( 3 )通过环金属化膦芳基配体与氢化物的偶联发生可逆的分子内C芳基-H还原消除,产生到正式的 Fe(0)–Zn(II) 物种。添加 CO 会破坏这种平衡,得到具有配位 Fe-Zn 键的 Cp*(Cy 2 PPh)(CO)Fe-ZnEt。值得注意的是,该系统实现了双金属 H 2加成,如一氢化物 Fe(μ-H)Zn 在与 D 2反应后转化为氘代二氢化物 Fe–(μ-D) 2 –Zn 所证明的。