Cyclopropenimine-Catalyzed Enantioselective Mannich Reactions of <i>tert</i>-Butyl Glycinates with <i>N</i>-Boc-Imines
作者:Jeffrey S. Bandar、Tristan H. Lambert
DOI:10.1021/ja407277a
日期:2013.8.14
shown to catalyze Mannichreactions between glycine imines and N-Boc-aldimines with high levels of enantio- and diastereocontrol. The reactivity of 1 is shown to be substantially greater than that of a widely used thiourea cinchona alkaloid-derived catalyst. A variety of aryl and aliphatic N-Boc-aldimines are effective substrates for this transformation. A preparative-scale reaction to deliver >90 mmol
An Efficient, Practical, and Enantioselective Method for Synthesis of Homoallenylamides Catalyzed by an Aminoalcohol-Derived, Boron-Based Catalyst
作者:Hao Wu、Fredrik Haeffner、Amir H. Hoveyda
DOI:10.1021/ja500374p
日期:2014.3.12
A practical catalytic method for enantioselective addition of an allene unit to aldimines is disclosed. Transformations are promoted by an in-situ-generated B-based catalyst that is derived from a simple, robust, and readily accessible (in multigram quantities) chiral aminoalcohol. A range of aryl-, heteroaryl-, and alkyl-substituted homoallenylamides can be obtained in 66–91% yield and 84:16 to >99:1