Copper-Catalyzed Divergent Addition Reactions of Enoldiazoacetamides with Nitrones

Catalyst-controlled
divergent addition reactions of enol­diazo­acetamides
with nitrones have been developed. By using copper­(I) tetrafluoroborate/bisoxazoline
complex as the catalyst, a [3+3]-cycloaddition reaction was achieved
with excellent yield and enantioselectivity under exceptionally mild
conditions, which represents the first highly enantioselective base-metal-catalyzed
vinylcarbene transformation. When the catalyst was changed to copper­(I)
triflate, Mannich addition products were formed in high yields with
near exclusivity under otherwise identical conditions.

已开发出催化剂调控的烯基重氮乙酰胺（enoldiazoacetamides）与硝酮（nitrones）的发散型加成反应。采用四氟硼酸铜(I)（copper(I) tetrafluoroborate）/双恶唑啉（bisoxazoline）配合物作为催化剂，可在极为温和的反应条件下实现[3+3]环加成反应，该反应收率优异且对映选择性出色，代表首例非贵金属催化的高对映选择性乙烯基卡宾（vinylcarbene）转化反应。当将催化剂更换为三氟甲磺酸铜(I)（copper(I) triflate）时，在其余反应条件完全一致的情况下，可高收率、近乎专一性地得到曼尼希加成（Mannich addition）产物。