Synthesis of amino allenes via reaction of α-aminoalkylcuprates with propargyl substrates
作者:R.Karl Dieter、Lois E Nice
DOI:10.1016/s0040-4039(99)00778-9
日期:1999.6
α-Aminoalkylcuprates prepared from carbamates via sequential deprotonation and treatment with CuCN·2LiCl react with propargyl bromides, mesylates, tosylates, acetates, and epoxides to afford amino allenesvia a SN2′ substitution process. Propargyl bromides and sulfonates give good yields of amino allenes while the acetates afford low yields. Substrates undergo regiospecific SN2′ substitution and the
由氨基甲酸酯经顺序去质子化制得的α-氨基烷基铜酸酯,并用CuCN·2LiCl处理,与炔丙基溴,甲磺酸酯,甲苯磺酸酯,乙酸酯和环氧化物反应,经S N 2'取代过程制得氨基丙二烯。炔丙基溴和磺酸盐提供了良好的氨基丙二烯收率,而乙酸酯提供了低收率。底物进行区域特异性S N 2'取代,使用Sc(OTf)3可提高炔丙基环氧化物的氨基丙二烯收率。Boc保护的α-氨基丙二烯可以环化为恶唑烷酮或脱保护得到游离胺。
Synthesis of 3-Pyrrolines, Annulated 3-Pyrrolines, and Pyrroles from α-Amino Allenes
作者:R. Karl Dieter、Huayun Yu
DOI:10.1021/ol016654+
日期:2001.11.1
[GRAPHICS]alpha -Amino allenes, readily prepared from reaction of alpha-(N-carbamoyl)alkylcuprates with propargyl substrates followed by N-Boc deprotection, are converted in high yields to pyrrolines with AgNO3. Palladium-catalyzed cyclization of amino allenes affords either the pyrroline or the pyrrole depending on reaction conditions and provides for introduction of an aryl substituent at the C-3 position of the pyrroline or pyrrole. Enantioenriched pyrrolines are readily prepared from scalemic propargyl alcohols.