Direct Conversion of Phosphonates to Phosphine Oxides: An Improved Synthetic Route to Phosphines Including the First Synthesis of Methyl JohnPhos
作者:Alexander J. Kendall、Chase A. Salazar、Patrick F. Martino、David R. Tyler
DOI:10.1021/om500854u
日期:2014.11.10
reaction intermediate. A diverse array of phosphonates was converted to phosphine oxides using a variety of Grignard reagents for direct carbon–phosphorus functionalization. This new methodology especially simplifies the synthesis of dimethylphosphino (RPMe2)-type phosphines by using air-, water-, and silica-stable intermediates. To highlight this reaction, a new Buchwald-type ligand ([1,1′-biphenyl]-
Direct Aryloxylation/Alkyloxylation of Dialkyl Phosphonates for the Synthesis of Mixed Phosphonates
作者:Hai Huang、Johanna Denne、Chou‐Hsun Yang、Haobin Wang、Jun Yong Kang
DOI:10.1002/anie.201802082
日期:2018.5.28
A strategy for the direct functionalization strategy of inertial dialkyl phosphonates with hydroxy compounds to afford diverse mixed phosphonates with good yields and functional‐group tolerance has been developed. Mechanistic investigations involving both NMR studies and DFT studies suggest that an unprecedented highly reactive PV species (phosphoryl pyridin‐1‐ium salt), a key intermediate for this
Phosphonates containing sulfur and selenium. Synthesis of vinylphosphonates bearing α-sulfenyl, α-selenenyl, α-sulfinyl and α-seleninyl moieties and studies on nucleophilic addition
作者:Wanda H. Midura、Jerzy A. Krysiak
DOI:10.1016/j.tet.2004.10.026
日期:2004.12
efficiently to α-phosphorylvinyl sulfoxides or α-phosphorylvinyl selenides depending on the reaction conditions. Oxidation of α-phosphorylvinyl selenides and subsequent thermolysis of selenoxides afford alkynylphosphonates. Studies of the stereochemical course of nucleophilic addition to α-phosphoryl sulfoxides show high facial stereoselectivity of the reaction, however, epimerisation at the α-carbon atom leads
Addition of elemental selenium to phosphonate carbanions- - a key step in the synthesis of vinylphosphonates. A new synthetic approach to 1,4-dicarbonyl systems.
A convenient synthesis of vinylphosphonates which involves addition of elemental selenium to phosphonate carbanions followed by alkylation and selenoxide elimination is described. A general approach to 1,4-dicarbonyl systems based on diethyl α-methylthiovinylphosphonate is also reported.
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