A macrocyclic sulfate (MCS)‐based approach to monodisperse poly(ethyleneglycols) (M‐PEGs) and their monofunctionalized derivatives has been developed. Macrocyclization of oligo(ethyleneglycols) (OEGs) provides MCS (up to a 62‐membered macrocycle) as versatile precursors for a range of monofunctionalized M‐PEGs. Through iterative nucleophilic ring‐opening reactions of MCS without performing group
Generation of (nonafluoro-tert-butoxy)methyl ponytails for enhanced fluorous partition of aromatics and heterocycles
作者:Xi Zhao、Wing Yan Ng、Kai-Chung Lau、Alana E. C. Collis、István T. Horváth
DOI:10.1039/c2cp23113a
日期:——
The reaction of sodium perfluoro-tert-butoxide with benzylic carbon–bromide bond(s) leads to the formation of (nonafluoro-tert-butoxy)methyl ponytail(s), which can enhance the fluorous solubility and partition of aromatics and heterocycles.
Perfluoroalkyl hypobromites: synthesis and reactivity with some fluoroalkenes
作者:John D.O. Anderson、Darryl D. DesMarteau
DOI:10.1016/0022-1139(96)03400-8
日期:1996.4
prepared by the reaction of bromine(I) fluorosulfate with perfluorinated tertiary alkoxides of general formula RfC (CF3)2ONa where RfCF3 or CF3CF2. These hypobromites are of lower thermal stability but they behave similarly to analogous hypochlorites and decompose rapidly above −20 °C to give CF3C(O)CF3 and either CF3Br or CF3CF2Br. New polyfluoroethers generated from the reaction of perfluoroalkyl
Synthesis of optically active α-(nonafluoro-tert-butoxy)carboxylic acids
作者:Tamás Csóka、Anikó Nemes、Dénes Szabó
DOI:10.1016/j.tetlet.2013.01.072
日期:2013.3
Three novel α-(nonafluoro-tert-butoxy)carboxylic esters were synthesized by two methods: the Mitsunobu reaction of optically active (S)-α-hydroxycarboxylic esters and the Williamson synthesis starting from the corresponding O-mesyl derivatives. Both procedures from ethyl (S)-lactate resulted in the formation of a fluorous optically active (R)-lactic acid ester derivative, while the reactions from methyl
通过两种方法合成了三种新颖的α-(九氟叔丁基氧基)羧酸酯:旋光性(S)-α-羟基羧酸酯的Mitsunobu反应和从相应的O-甲磺酰基衍生物开始的Williamson合成。来自(S)-乳酸乙酯的两种方法均形成氟光学活性(R)-乳酸酯衍生物,而来自(S)-扁桃酸甲酯的反应在消旋作用下进行。描述了这种消旋作用的建议机制。在Mitsunobu条件下,(S)-苯基乳酸甲酯的转化也具有立体特异性,但其O的反应-甲磺酰基衍生物产生取代和消除产物的混合物。通过上述酯的水解制备的α-(九氟叔丁氧基)羧酸的光学纯度通过1 H NMR光谱法测定。
Synthesis of Molybdenum(VI) Neopentylidene Neopentylidyne Complexes
作者:Hosein Tafazolian、Richard R. Schrock、Peter Müller
DOI:10.1021/acs.organomet.9b00412
日期:2019.8.12
2Pyr)(PMe2Ph)2 (2a) as a pale yellow solid in 76% yield, and 2a reacts with Ph3SiOH to give a mixture of syn and anti Mo(C-t-Bu)(CH-t-Bu)(OSiPh3)(PMe2Ph)2 (3a) in 84% yield. All three compounds tend to lose PMe2Ph to give 14e monophosphine complexes with the formulas Mo(C-t-Bu)(CH-t-Bu)(X)(PMe2Ph) (X = Cl, Me2Pyr, or OSiPh3), none of which could be isolated. X-ray studies show the structures of 1,