Ag-Catalyzed Asymmetric Mannich Reactions of Enol Ethers with Aryl, Alkyl, Alkenyl, and Alkynyl Imines
作者:Nathan S. Josephsohn、Marc L. Snapper、Amir H. Hoveyda
DOI:10.1021/ja049388e
日期:2004.3.1
An efficient catalytic and enantioselective method (up to >98% ee) for Mannich reactions between trimethylsilyl enol ethers derived from acetone and acetophenone and aryl, alkenyl, alkynyl, and alkyl imines is disclosed. A large variety of beta-amino ketones can be synthesized in the presence of 1-5 mol % AgOAc and an inexpensive and readily available amino acid-derived phosphine. All Ag-catalyzed
A Highly Efficient and Practical Method for Catalytic Asymmetric Vinylogous Mannich (AVM) Reactions
作者:Emma L. Carswell、Marc L. Snapper、Amir H. Hoveyda
DOI:10.1002/anie.200603496
日期:2006.11.6
Efficient and Practical Ag-Catalyzed Cycloadditions between Arylimines and the Danishefsky Diene
作者:Nathan S. Josephsohn、Marc L. Snapper、Amir H. Hoveyda
DOI:10.1021/ja030033p
日期:2003.4.1
An efficient Ag-catalyzed method for asymmetric addition of the Danishefsky diene to various aryl imines to afford cycloadducts in > or =89% ee and > or =85% isolated yield is reported. Reactions are effected with 0.1-1 mol % catalyst (4 degrees C), and the chiral ligand is readily prepared from commercially available materials, including the inexpensive i-Leu. These catalytic asymmetric cycloadditions can be carried out without the use of solvent or with undistilled THF in air. A first generation supported chiral catalyst that effectively promotes the cycloaddition reaction and can be recycled (five cycles) is described.