Remarkable Reaction Rate and Excellent Enantioselective Direct α-Amination of Aldehydes with Azodicarboxylates Catalyzed by Pyrrolidinylcamphor-Derived Organocatalysts
Remarkable reaction rate and excellent enantioselective direct α-amination of unmodified aldehydes with various azodicarboxylates was catalyzed by pyrrolidinylcamphor organo-catalyst 2a (5 mol-%) to provide the desired aminated products with excellent chemical yields and high to excellent levels of enantioselectivity (up to >99%ee) at 0 °C in CH 2 Cl 2 .
Pyrrolidinyl-Camphor Derivatives as a New Class of Organocatalyst for Direct Asymmetric Michael Addition of Aldehydes and Ketones to β-Nitroalkenes
作者:Ying-Fang Ting、Chihliang Chang、Raju Jannapu Reddy、Dhananjay R. Magar、Kwunmin Chen
DOI:10.1002/chem.201000483
日期:——
Practical and convenient synthetic routes have been developed for the synthesis of a new class of pyrrolidinyl–camphor derivatives (7 a–h). These novel compounds were screened as catalysts for the direct Michael addition of symmetrical α,α‐disubstituted aldehydes to β‐nitroalkenes. When this asymmetric transformation was catalyzed by organocatalyst 7 f, the desired Michael adducts were obtained in