Controlled Monohalogenation of Phosphonates, Part II: Preparation of Pure Diethyl α-Monohalogenated Alkylphosphonates
作者:Bogdan Iorga、Frédéric Eymery、Philippe Savignac
DOI:10.1055/s-2000-6375
日期:——
The reaction of diethyl alkylphosphonates with chlorotrimethylsilane in the presence of lithium diisopropylamide leads to the corresponding diethyl 1-lithio(trimethylsilyl)alkylphosphonates which are cleanly halogenated (X = F, Cl, Br, I) with electrophilic reagents and then deprotected to give pure diethyl a-monohalogenoalkylphosphonates. The reaction has been extended by the onepot conversion of
Nickel-Catalyzed Enantioconvergent Reductive Hydroalkylation of Olefins with α-Heteroatom Phosphorus or Sulfur Alkyl Electrophiles
作者:Shi-Jiang He、Jia-Wang Wang、Yan Li、Zhe-Yuan Xu、Xiao-Xu Wang、Xi Lu、Yao Fu
DOI:10.1021/jacs.9b09415
日期:2020.1.8
bond formation reactions have been made in recent years through the use of transition-metal-catalyzed cross-couplingreactions of racemic secondary alkyl electrophiles with organometallic reagents. Herein, we report a general process for the asymmetric construction of alkyl-alkyl bonds adjacent to heteroatoms, namely, a nickel-catalyzed enantioconvergent reductive hydroalkylation of olefins with α-heteroatom
Novel guanidated aminophosphonic acid compounds their use as biocides and their intermediates. The compounds are guanidated N-(aminoalkyl) aminoalkanephosphonic acid derivatives and are characterized in that they comprise both a phosphonic acid type group and at least one guanidino group and also in that they are based on alkylene amines. The compounds have the general formula: ##STR1## wherein Z and Z' are hydrogen, a lower alkyl group or an alkali metal, Y is hydrogen or an amidine group, m is 1-3, n is 4-16 and p is 1-3. The compounds can be prepared by reacting a halogenoalkanephosphonic acid compound with an alkylene di- or polyamine followed by guanidation of the so obtained product. The compounds are particularly useful as fungicides and especially as fungicides for industrial purposes.
A simple and straightforward method for the synthesis of α-substituted ethylphosphonates via diimide reduction strategy is described. With K3PO4 or Na2CO3 as the basic additive, a range of terminal alkenylphosphonates underwent efficient reduction by diimide generated from 2-nitrobenzenesulfonylhydrazide (NBSH) under room temperature. The high functional group tolerance of this methodology is also
描述了一种通过二酰亚胺还原策略合成α-取代的乙基膦酸酯的简单直接的方法。以K 3 PO 4或Na 2 CO 3为基本添加剂,在室温下,一定范围内的末端链烯基膦酸酯被2-硝基苯磺酰肼(NBSH)生成的二酰亚胺有效还原。还证明了该方法具有较高的官能团耐受性。此外,我们的方法具有安全性高,反应条件温和,对设备的要求低以及化学选择性高的特点。
Electrochromic compounds
申请人:Ntera Limited
公开号:EP1443091A1
公开(公告)日:2004-08-04
The invention concerns electrochromic compounds of the general formula I
These compounds may be used in electrochromic devices, especially electrochromic devices comprising nanostructured films.