A Stereodivergent Approach to Chiral Nonracemic N-Protected α,α-Dialkylated Amino Acids
作者:Claude Spino、Cédrickx Gobdout
DOI:10.1021/ja037078a
日期:2003.10.1
Menthyl carboxaldehyde is used as a chiral auxiliary to make quaternary amino acids of either configuration via a stereodivergent approach that includes an SN2' displacement by a cuprate reagent and a Curtius rearrangement as key steps.
DUBAC, J.;LAPORTERIE, A.;ILOUGHMANE, H.;PILLOT, J. P.;DELERIS, G.;DUNOGUE+, J. ORGANOMET. CHEM., 1985, 281, N 2-3, 149-162
作者:DUBAC, J.、LAPORTERIE, A.、ILOUGHMANE, H.、PILLOT, J. P.、DELERIS, G.、DUNOGUE+
DOI:——
日期:——
Ène-réactivité d'allylsilanes: Fonctionnalisation et régiochimie
The hydroperoxidation of various allylsilanes by singletoxygen has been studied. The regioselectivity of this reaction compared to those of ethyl azodicarboxylate and 4-phenyl-1,2,4-triazoline-3,5-dione, is discussed. Mechanisms are considered in the general field of the ene reaction applied to allylic organometallic Group IVB compounds. The structures of the new products (alcohols, urazoles, hydrazines)
The cyclopropylcarbinyl route to γ-silyl carbocations
作者:Xavier Creary
DOI:10.3762/bjoc.15.170
日期:——
mesylates and triflates with substituents on the 1-position. These substrates all solvolyze in CD3CO2D to give products derived from cyclopropylcarbinylcations that undergo further rearrangement to give 3-trimethylsilylcyclobutyl cations. These 3-trimethylsilylcyclobutyl cations are stabilized by a long-range rear lobe interaction with the γ-trimethylsilyl group. When the substituent is electron-withdrawing
已经制备了顺-1-羟甲基-2-三甲基甲硅烷基环丙烷的甲磺酸酯衍生物,以及许多相关的甲磺酸酯和在1-位带有取代基的三氟甲磺酸酯。这些底物全部在CD 3 CO 2 D中溶剂溶解,得到衍生自环丙基羰基阳离子的产物,该产物经过进一步重排得到3-三甲基甲硅烷基环丁基阳离子。这些3-三甲基甲硅烷基环丁基阳离子通过与γ-三甲基甲硅烷基的长距离后叶相互作用而稳定化。当取代基是吸电子的(CF 3,CN或CO 2 CH 3),形成大量的双环丁烷产物。双环丁烷是从阳离子中间体中消除了γ-三甲基甲硅烷基的结果,该中间体具有异常长的Si-C键。反式-1-羟甲基-2-三甲基甲硅烷基环丙烷的甲磺酸酯和三氟甲磺酸酯衍生物和1-取代的类似物的溶剂化化学性质可能完全不同,因为这些底物通常不会导致3-三甲基甲硅烷基环丁基阳离子。