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论文类型：期刊论文

发表时间：2017-08-25

发表刊物：NATURE COMMUNICATIONS

收录刊物：SCIE、PubMed、Scopus

卷号：8

期号：1

页面范围：361

ISSN号：2041-1723

摘要：Modifying electron transfer pathways is essential to controlling the regioselectivity of heterogeneous photochemical transformations relevant to saturated carbonyls, due to fixed catalytic sites. Here we show that the interpenetration of metal-organic frameworks that contain both photoredox and asymmetric catalytic units can adjust the separations and electron transfer process between them. The enforced close proximity between two active sites via framework interpenetration accelerates the electron transfer between the oxidized photosensitizer and enamine intermediate, enabling the generation of 5 pi e(-) beta-enaminyl radicals before the intermediates couple with other active species, achieving beta-functionalized carbonyl products. The enriched benzoate and iminium groups in the catalysts provide a suitable Lewis-acid/base environment to stabilize the active radicals, allowing the protocol described to advance the beta-functionalization of saturated cyclic ketones with aryl ketones to deliver gamma-hydroxyketone motifs. The homochiral environment of the pores within the recyclable frameworks provides additional spatial constraints to enhance the regioselectivity and enantioselectivity.