Second generation CaSH (Camphor Sulfonyl Hydrazine) organocatalysis. asymmetric diels-alder reactions and isolation of the catalytic intermediate

Qinghua Li, Wai Yeung Wong, Wing Hong Chan, Albert W M Lee

Research output: Journal article publicationJournal articleAcademic researchpeer-review

22 Citations (Scopus)

Abstract

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. KGaA, Weinheim.
Original languageEnglish
Pages (from-to)2142-2146
Number of pages5
JournalAdvanced Synthesis and Catalysis
Volume352
Issue number13
DOIs
Publication statusPublished - 10 Sep 2010
Externally publishedYes

Keywords

  • Asymmetric diels-alder reaction
  • Camphor sulfonyl hydrazine
  • CaSH
  • Hydrazines
  • Organocatalysis

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

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