In:
European Journal of Organic Chemistry, Wiley, Vol. 2017, No. 46 ( 2017-12-15), p. 6878-6881
Abstract:
Asymmetric synthesis involving photochemical dimerization of a prochiral flavonoid derivative in solution without any chiral source was achieved. Irradiation of ethyl 6‐bromochromonecarboxylate in solution efficiently gave a C 2 ‐chiral anti ‐head‐to‐head dimer in excellent chemical yield with good quantum efficiency ( Φ 365 = 0.15). X‐ray crystallographic analysis revealed that the dimer crystallized as a conglomerate of C 2 space group. The crystalline dimer precipitated upon irradiation of the monomer in solution, and indirect racemization of the dimer through a reversible photoreaction in solution and selective crystallization simultaneously occurred to give the C 2 ‐chiral dimer in optically active form with up to 80 % ee . Optically active photoproducts could be obtained by simply irradiating achiral materials in solution without an external chiral source.
Type of Medium:
Online Resource
ISSN:
1434-193X
,
1099-0690
DOI:
10.1002/ejoc.v2017.46
DOI:
10.1002/ejoc.201701457
Language:
English
Publisher:
Wiley
Publication Date:
2017
detail.hit.zdb_id:
1475010-7
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