Organocatalytic α-Allylation of α-Branched Aldehydes by Synergistic Catalysis of Brønsted Acids and Amines
作者:Filip Stanek、Maciej Stodulski
DOI:10.1002/ejoc.201600725
日期:2016.10
Herein, we describe the first, fully organocatalytic Tsuji–Trost-type direct α-allylation of α-branched aldehydes by the combined use of N-triflyl amides and secondary amines. Aliphatic, aromatic aldehydes as well as allyl alcohols are converted into the corresponding α-allylated products in moderate to high yields.
This paper describes an enantioselective intermolecular allylicaminationcatalyzed by a chiral Brønsted acid via a possible chiral contact ion pair intermediate. A variety of symmetrical or unsymmetrical allylic alcohols can be smoothly aminated to afford the desired products in moderate to high yields with good enantioselectivities and/or regioselectivities.
Oxime 1, 3, 4, 6, 7, 9 liefern bei der Umsetzungmit Salpetersäure/Natriumnitrit oder Distickstofftetroxid 4‐Oxo‐4H‐pyrazol‐1,2‐bis‐oxide 2, 5, 8, 10, deren Struktur durch Synthese und spektroskopische Untersuchungen geklärt wird. In essigsaurer Lösung erhält man, ausgehend von den Oximen 1, 3a–d, 6a, Gemische aus 4‐Oxo‐4H‐pyrazol‐1,2‐bis‐oxiden und 4‐Hydroximino‐4H‐pyrazol‐1,2‐bis‐oxiden, die dünnsch