Second Generation CaSH (Camphor Sulfonyl Hydrazine) Organocatalysis. Asymmetric Diels-Alder Reactions and Isolation of the Catalytic Intermediate
作者:Qinghua Li、Wai-Yeung Wong、Wing-Hong Chan、Albert W. M. Lee
DOI:10.1002/adsc.201000438
日期:2010.9.10
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