Oxidative Phosphonylation of Aromatics with Ammonium Cerium(IV) Nitrate Arylphosphonates 5 and 6 can be prepared in good yields in a one-step synthesis starting from arenes with tri- or diethylphosphites and cerium ammonium nitrate (CAN) as oxidant. The selectivity of the oxidative phosphonylation is relatively low; the reactive species is a phosphite radical cation.
Manganese(III)-mediated direct phosphonylation of arenes
作者:Wei Xu、Jian-Ping Zou、Wei Zhang
DOI:10.1016/j.tetlet.2010.03.029
日期:2010.5
Manganese (III)-promoted direct phosphonylation of mono- and disubstituted arenes with dialkylphosphite afforded regioselective dialkylphosphonates in good yields. The reactions can apply to arenesbearing electron-donating groups and electron-withdrawinggroups such as ester and nitrile.
There are provided a compound capable of being a novel ligand allowing regioselective borylation to be performed in the aromatic borylation reaction, and a catalyst using the same compound. There is provided a bipyridyl compound represented by a general formula (
1
): (wherein A represents a single bond, a vinylene group or an ethynylene group;
X represents an oxygen atom or a sulfur atom;
n pieces of R
1
may be the same or different, and R
1
represents a hydrogen atom, a halogen atom, an optionally substituted hydrocarbon group, an optionally substituted alkoxy group, an optionally substituted aryloxy group, an optionally substituted amino group, a cyano group, a nitro group, or an alkoxycarbonyl group, or two adjacent R
1
may form a saturated or unsaturated ring structure optionally containing a hetero atom together with the carbon atoms bonded to the two R
1
;
R
2
represents a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted alkoxy group, or an optionally substituted aryloxy group; and
n represents a number of
1
to
4
).
Photoinduced phosphonation of aryl triflates with trialkyl phosphites via a tandem single-electron-transfer, C–O bond cleavage and Arbuzov rearrangement process in the absence of transition-metal and external photosensitizer is reported herein. The protocol features good functional group compatibility and mild reaction conditions, providing various aryl phosphates in good to high yields. Furthermore
anodic oxidation proceeds either via phosphiniumradicalcations, which then attack the arenes electrophilically, or via arene radicalcations, which add the trialkylphosphite as nucleophile. Aryl phosphonates are also obtained in good yield by chemical oxidation with peroxodisulfate/AgNO3 in acetonitrile/water or glacial acetic acid. The diethylphosphinium radicalcation, formed from diethylphosphite by