An Expedient and Practical Method for the Synthesis of a Diverse Series of Cyclopropane α-Amino Acids and Amines
作者:Ryan P. Wurz、André B. Charette
DOI:10.1021/jo035596y
日期:2004.2.1
described. Nitrocyclopropane carboxylates can be readily prepared through treatment of α-nitroesters and iodobenzene diacetate or α-nitro-α-diazoesters with a Rh(II) catalyst and an olefin. Reduction of the nitro group using zinc/HCl in i-PrOH affords substituted cyclopropane α-amino esters in modest to high yields (54−99%). A “one-pot” procedure involving sequential cyclopropanation and reduction is described
Nitrocyclopropanes from nitrodiazomethanes. Preparation and reactivity
作者:P.E. O'Bannon、William P. Dailey
DOI:10.1016/s0040-4020(01)89052-9
日期:——
Nitrodiazo compounds cyclopropanate electron rich alkenes in the presence of rhodium(II) acetate. The yields and diastereoselectivities are dependent on both the alkene and the nitrodiazo precursor. Nitrocyclopropanecarboxylates undergo ring opening, reduction and hydrolysis.
A procedure for the use ofnitromethane as an iodonium ylide precursor has been developed. Electron-rich olefins are cyclo-propanated with nitromethane in the presence ofbis(acetoxy)iodobenzene, a base and a Rh(II) catalyst to provide nitrocyclopropanes in moderate to good yields.
Photocatalytic bromonitroalkylations of activated and unactivated olefins with broad scope become possible in the presence of CuI-photocatalysts. The key to success for this transformation is the highlyefficient interaction of CuII with radical intermediates, which can even outperform a highly favorable cyclization of a transient to a persistent radical.
在 Cu I -光催化剂存在下,具有广泛范围的活化和未活化烯烃的光催化溴硝基烷基化成为可能。这种转化成功的关键是 Cu II与自由基中间体的高效相互作用,它甚至可以胜过从瞬态自由基到持久自由基的高度有利的环化。
OBANNON, P. E.;DAILEY, WILLIAM P., J. ORG. CHEM., 55,(1990) N, C. 353-355