Thermodynamic Stability and Reactivity of Silylated Bis(oxy)iminium Ions
作者:Yulia A. Khomutova、Vladimir O. Smirnov、Herbert Mayr、Sema L. Ioffe
DOI:10.1021/jo070633x
日期:2007.11.1
trialkylsilyl triflates was investigated by applying NMR techniques. In several cases, a flexible nitronate−bis(oxy)iminium ion (as an ion pair with triflate as counterion) equlibrium was found, and its thermodynamic parameters were determined. Elevation of temperature or dilution shifts this equilibrium toward the reactants. Activation parameters for the C,C-coupling reaction of silylated bis(oxy)iminium ions
Stereocontrolled Oxidation of Six-Membered Cyclic O-Silyl Nitroso Acetals with mCPBA: Umpolung Approach to Functionalized Nitro Compounds
作者:Anastasia S. Naumova、Andrey A. Mikhaylov、Marina I. Struchkova、Yulia A. Khomutova、Vladimir A. Tartakovsky、Sema L. Ioffe
DOI:10.1002/ejoc.201101768
日期:2012.4
cyclic nitroso acetals 2 are smoothly oxidized with meta-chloroperbenzoic acid to δ-nitro alcohols 3 or γ-nitro carbonyl compounds 4 with the retention of their relative configurations of stereocenters (diastereomeric ratio > 10:1). The reaction sequence – the generation of diastereomerically pure six-membered cyclic nitronates 1 from simple aliphaticnitrocompounds (AN), C–C coupling of 1 with π-nucleophiles
Six-membered cyclic nitronates as Brönsted bases: protonation and rearrangement into butyrolactone oximes
作者:Vladimir O. Smirnov、Yulia A. Khomutova、Sema L. Ioffe
DOI:10.1016/j.mencom.2008.09.009
日期:2008.9
The protonation of six-membered cyclic nitronates (SMCNs) was studied by low-temperature NMR spectroscopy, and an efficient preparative procedure for acid-induced rearrangement of SMCNs into oximes of substituted butyrolactones was developed.
Stereoselective Amine Addition to Six-Membered Cyclic Nitronates Promoted by Silyl Triflate
作者:Andrey A. Mikhaylov、Alexander D. Dilman、Yulia A. Khomutova、Dmitry E. Arkhipov、Alexander A. Korlyukov、Sema L. Ioffe
DOI:10.1002/ejoc.201300511
日期:2013.9
N‐Silylamines add to six‐membered nitronates with high diastereoselectivity. The reaction follows an original mechanism in which thermodynamic control plays the key role.
New C−C Coupling Reaction of Cyclic Nitronates with Carbon Nucleophiles. Umpolung of the Conventional Reactivity of Nitronates
作者:Vladimir O. Smirnov、Sema L. Ioffe、Alexander A. Tishkov、Yulia A. Khomutova、Ivan D. Nesterov、Michael Yu. Antipin、William A. Smit、Vladimir A. Tartakovsky
DOI:10.1021/jo048944k
日期:2004.11.1
Cyclic six-membered nitronates 1 are involved in diastereoselective C−Ccoupling reactions with various nucleophiles in the presence of either catalytic or stoichiometric amounts of TBDMSOTf to give the previously unknown N-siloxytetrahydrooxazines. The intermediacy of N,N-bis(oxy)iminium cations was proven by NMR data.