Synthesis, Properties, and Crystal Structure of Silyl Nitronates (Silyl Esters ofaci-Nitroalkanes): Towards theSN2 Reaction Path with Retention of Configuration at Silicon
作者:Ernest W. Colvin、Albert K. Beck、Bahram Bastani、Dieter Seebach、Yasushi Kai、Jack D. Dunitz
DOI:10.1002/hlca.19800630320
日期:1980.4.23
the preparation of silyl nitronates is described (see 1–10). NMR. spectral investigations indicate a rapid 1,3-silylmigration process, with an activation energy of about 10 kcal mol−1. X-ray crystallographic studies on the silyl nitronates 3 and 8 show structures that lean towards an SN2 retention pathway at silicon.
描述了一种高效,灵活的制备甲磺酸硅烷基酯的方法(参见1-10)。核磁共振。光谱研究表明,快速的1,3-甲硅烷基迁移过程具有约10 kcal mol -1的活化能。对甲硅烷基磺酸盐3和8的X射线晶体学研究表明,其结构倾向于向S N 2保留在硅的路径。
The Hydroformylation of Nitroalkenes with Rhodium Carbonyl
作者:Masahiko Takesada、Hachiro Wakamatsu
DOI:10.1246/bcsj.43.2192
日期:1970.7
poor yield in the presence of dicobalt octacarbonyl. Under hydroformylation conditions, nitrobenzene is hydrogenated to aniline above 150°C with rhodiumcarbonyl and at 125°C with cobalt carbonyl. The hydroformylation of nitroalkenes with rhodiumcarbonyl is described. 4-Nitrostyrene gives isomeric (4-nitrophenyl)-propionaldehydes in a 96% yield. 3-Nitropropene-1 gives C4-nitroaldehydes, mostly 2-
Variant G74C of arylmalonatedecarboxylase (AMDase) from Bordatella bronchoseptica has a unique racemising activity towards profens. By protein engineering, variant G74C/V43A with a 20‐fold shift towards promiscuous racemisation was obtained, based on a reduced activity in the decarboxylation reaction and a two‐fold increase in the racemisation activity. The mutant showed an extended substrate range
A CONVENIENT SYNTHESIS OF KETOXIMES FROM GRIGNARD REAGENTS AND NITRO COMPOUNDS ACTIVATED BY<i>N</i>,<i>N</i>-DIMETHYLCHLOROMETHYLENIMINIUM CHLORIDE
作者:Tamotsu Fujisawa、Yoshitsugu Kurita、Toshio Sato
DOI:10.1246/cl.1983.1537
日期:1983.10.5
Ketoximes were synthesized in high yields with a newcarbon–carbonbondformation by regioselective nucleophilic attack of Grignard reagents at the α-position of aci-nitroalkanes activated by N,N-dimethylchloromethyleniminium chloride in the presence of a catalytic amount of copper(I) iodide under mild conditions.
Novel ruthenium(II) complexes were obtained as a result of a stoichiometric reaction of Grubbs’ benzylidene second generation catalysts with 3-nitropropene. These stable complexes, formally ruthenaisoxazole N-oxide derivatives, display activity in both metathesis and non-metathetic processes such as cycloisomerisation, isomerisation and transfer hydrogenation.