A Highly Efficient Method for the Synthesis of Nitrogen-containing Materials Using Umpolung Addition to Electron-Deficient Imines

我们已经报道了用铝试剂进行α -亚胺酯n -烷基化反应，得到了高产率的n -烷基化产物。在本项目中，我们研究了β， γ -烷基- α -亚胺酯的高度区域选择性n -烷基化，以及随后与原位生成的二烯醇酯的定向乙烯醛反应。同时发现，烯烃部分的亚砜基提高了这两个步骤的选择性，通过抗巯基消除生成3-氨基-2-吡咯酮。此外，在两种不同的格氏试剂作用下，α -酰基氧亚胺酯在氮原子上得到了不同取代基的对应的二烷基化产物。通过氧化反应和亲核加成反应，得到了含不同取代基的N，N， c -三烷基化产物。

We have already reported that the N-alkylation reaction of alpha-iminoester proceeds using aluminum reagents to give the N-alkylation products in high yields. In the present project, we investigated highly regioselective N-alkylation of beta,gamma-alkenyl-alpha-iminoesters and subsequent directed vinylogous aldol reaction with in situ generated dienolates. It was also found that the sulfenyl group of the alkene part improved the selectivity of both steps, leading to the formation of 3-amino-2-pyrones by anti-elimination of thiols. Furthermore, on treatment with two different Grignard reagents, alpha-acyloxyimino esters gave the corresponding dialkylation products with different substituents on the nitrogen atom. N,N,C-Trialkylated products with all different substituents were obtained via the oxidation and the nucleophilic addition reaction to the resulting iminium salts.