In:
Angewandte Chemie, Wiley, Vol. 130, No. 7 ( 2018-02-12), p. 1931-1935
Abstract:
Asymmetric construction of halogenated quaternary carbon centers under mild reaction conditions remains challenging. Reported here is an unprecedented and highly stereoselective Brønsted base catalyzed [4+2] cycloaddition between either α‐chloro‐ or α‐bromoaldehydes and cyclic enones. The key intermediate, an α‐halogenated enolate, is susceptible to dehalogenation and can be stabilized and stereochemically controlled using bifunctional tertiary amines. This method provides facile access to a collection of optically pure bicyclic dihydropyrans having three contiguous stereocenters, including a halogen‐bearing quaternary carbon center. Of note, the product can be transformed in situ into densely functionalized spirocyclopropanes in a highly efficient and stereoselective manner.
Type of Medium:
Online Resource
ISSN:
0044-8249
,
1521-3757
DOI:
10.1002/ange.201711813
Language:
English
Publisher:
Wiley
Publication Date:
2018
detail.hit.zdb_id:
505868-5
detail.hit.zdb_id:
506609-8
detail.hit.zdb_id:
514305-6
detail.hit.zdb_id:
505872-7
detail.hit.zdb_id:
1479266-7
detail.hit.zdb_id:
505867-3
detail.hit.zdb_id:
506259-7
Permalink