Department of Chemistry
Second generation CaSH (camphor sulfonyl hydrazine) organocatalysis. asymmetric diels–alder reactions and isolation of the catalytic intermediate
In one step, the well known chiral auxiliary, Oppolzer's camphor sultam, is turned into the new generation camphor sulfonyl hydrazine (CaSH II) organocatalyst. With the primary hydrazine functionality external to the tricyclic structure, CaSH II is active towards ketone substrates in asymmetric Diels-Alder reactions. The iminium intermediate of the catalytic cycle was isolated. When it was put back into the solution reaction system, the same level of yield and stereoselectivity was observed. Based on these observations, we argue that organocatlyst is actually an in situ chiral auxiliary. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
Asymmetric diels-alder reaction, Camphor sulfonyl hydrazine, CaSH, Hydrazines, Organocatalysis
Source Publication Title
Advanced Synthesis and Catalysis
Link to Publisher's Edition
Li, Qinghua, Wai-Yeung Wong, Wing-Hong Chan, and Albert W. M. Lee. "Second generation CaSH (camphor sulfonyl hydrazine) organocatalysis. asymmetric diels–alder reactions and isolation of the catalytic intermediate." Advanced Synthesis and Catalysis 352.13 (2010): 2142-2146.