Highly Enantioselective Catalytic Asymmetric [2+2] Cycloadditions of Cyclic α-Alkylidene β-Oxo Imides with Ynamides
作者:Kazuaki Enomoto、Harufumi Oyama、Masahisa Nakada
DOI:10.1002/chem.201406189
日期:2015.2.9
Highly enantioselective catalytic asymmetric [2+2] cycloadditions of cyclic α‐alkylidene β‐oxo imides with ynamides are described. The high reactivity of the cyclic α‐alkylidene β‐oxo imide allows the [2+2] cycloadditions of a hindered substrate with unreactive ynamides at low temperature. The X‐ray crystallographic analysis of the product suggests that the enantioselectivity of the [2+2] cycloaddition
描述了环状α-亚烷基β-氧代酰亚胺与乙酰胺的高度对映选择性催化不对称[2 + 2]环加成反应。环状α-亚烷基β-氧代酰亚胺的高反应性可在低温下将受阻底物与未反应的酰胺类化合物进行[2 + 2]环加成反应。产品的X射线晶体学分析表明,[2 + 2]环加成的对映选择性可以通过包含分子内氢键的螯合物模型很好地解释,其中环状α-亚烷基β-氧酰亚胺与Cu II通过两个酰亚胺羰基。产物中的酰亚胺基团可以转化为酰胺基,腈基和酯基;而且,它是可移动的。