Palladium/Xiao‐Phos‐Catalyzed Kinetic Resolution of
<i>sec</i>
‐Phosphine Oxides by
<i>P</i>
‐Benzylation
作者:Qiang Dai、Lu Liu、Junliang Zhang
DOI:10.1002/anie.202111957
日期:2021.12.20
rac-secondary phosphine oxides via the enantioselective P-benzylation process catalyzed by the palladium/Xiao-Phos was designed. Both, tert- and sec-phosphine oxides were delivered in good yield and excellent enantiopurity (selectivity factor up to 226.1). The synthetic utilities are further demonstrated by the facile preparation of several P-chiral compounds, precursors of bidentate ligands, and transition
Benzylic Phosphates in Friedel–Crafts Reactions with Activated and Unactivated Arenes: Access to Polyarylated Alkanes
作者:Gangaram Pallikonda、Manab Chakravarty
DOI:10.1021/acs.joc.5b02441
日期:2016.3.4
Easily reachable electron-poor/rich primary and secondary benzylic phosphates are suitably used as substrates for Friedel–Craftsbenzylation reactions with only 1.2 equiv activated/deactivatedarenes (no additional solvent) to access structurally and electronically diverse polyarylated alkanes with excellent yields and selectivities at room temperature. Specifically, diversely substituted di/triarylmethanes
the presence of gold nanoparticles supported on ZrO2 proceeded efficiently under mild reaction conditions to give the corresponding allyl sulfides in excellent yields. ZrO2-Supported gold nanoparticles showed excellent catalytic turnover and reusability. In addition, the C–O bonds of benzyl and propargyl phosphates underwent thioetherification to afford benzyl and propargyl sulfides. The reaction of
Nucleophilic addition to carbonyl compounds. competition between hard (amine) and soft (phosphite) nucleophile
作者:Roman Gancarz
DOI:10.1016/0040-4020(95)00634-k
日期:1995.9
reaction mixture, two nucleophiles: dialkyl phosphite and the amine compete for the electrophilic carbonylcompound. Reaction mixture composition studies, kinetic studies as well as theoretical calculations, indicate that the softer the carbonylcompound is, the faster it reacts with the softer phosphorus nucleophile and the slower it reacts with the harder amine nucleophile. It in turn results in
Remote C−H Activation of Phenyl-Substituted Alkenes by BH<sub>3</sub>·THF: Mechanism and Applications
作者:Jesús A. Varela、Diego Peña、Bernd Goldfuss、Kurt Polborn、Paul Knochel
DOI:10.1021/ol016215a
日期:2001.7.1
and, in particular, bicyclic alkenes with BH(3).THF at 50 degrees C provides, via a highlystereoselective 1,2-rearrangement and a remoteC-Hactivation, a diol in which the relative stereochemistry of three centers has been controlled. A mechanistic study provides general rules for remoteC-Hactivation and leads to new synthetic applications.