School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.
Org Lett. 2011 Feb 18;13(4):728-31. doi: 10.1021/ol102956x. Epub 2011 Jan 18.
N-Ts and N-Boc derivatives of 1,2-diamines and 1,2-amino alcohols are shown to undergo efficient Pd(II)-catalyzed aza-Wacker reactions with a large range of electron-deficient alkenes. The resulting enamine intermediate generally undergoes cyclization with the second heteroatom to form 1,3-heterocycles. The sequence facilitates the rapid synthesis of saturated oxazolidines, imidazolidines, and their derivatives. Use of N-L-valinol derivatives results in highly diastereoselective reactions, where the net stereochemical outcome diverges between N-Ts and N-Boc.
1,2-二胺和 1,2-氨基醇的 N-Ts 和 N-Boc 衍生物被证明能与多种缺电子烯烃进行高效的 Pd(II)催化的氮杂-Wacker 反应。所得烯胺中间体通常与第二个杂原子环化形成 1,3-杂环。这一序列促进了饱和恶唑烷、咪唑烷及其衍生物的快速合成。使用 N-L-缬氨醇衍生物可得到高度非对映选择性的反应,其中 N-Ts 和 N-Boc 的净立体化学结果不同。