Chiral N,N '-Dioxide-Scandium(III) Complex-Catalyzed Asymmetric Friedel-Crafts Alkylation Reaction of ortho-Hydroxybenzyl Alcohols with C3-Substituted N-Protected Indoles
Chiral N,N '-Dioxide-Scandium(III) Complex-Catalyzed Asymmetric Friedel-Crafts Alkylation Reaction of ortho-Hydroxybenzyl Alcohols with C3-Substituted N-Protected Indoles
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DOI：
10.1002/chem.201604088
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发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Feng Xiaoming
中科院分区：
文献类型：
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作者：
Zheng Jianfeng;Lin Lili;Dai Li;Yuan Xiao;Liu Xiaohua;Feng Xiaoming
The first Lewis acid catalyzed asymmetric Friedel–Crafts alkylation reaction ofortho‐hydroxybenzyl alcohols with C3‐substituted indoles is described. A chiralN,N′‐dioxide Sc(OTf)3complex served not only to promote formation ofortho‐quinone methides (o‐QMs) in situ but also induced the asymmetry of the reaction. This methodology enables a novel activation ofortho‐hydroxybenzyl alcohols, thus affording the desired chiral diarylindol‐2‐ylmethanes in up to 99 % yield and 99 %ee. A range of functional groups were also tolerated under the mild reaction conditions. Moreover, this strategy gives concise access to enantioenriched indole‐fused benzoxocines.
