Two-Step Synthesis of (Z)-3-Aryl-5-(arylmethylidene)butenolides by an Ivanov Reaction/Silver(I)-Catalyzed Lactonization/In Situ Dehydration Sequence
Two-Step Synthesis of (Z)-3-Aryl-5-(arylmethylidene)butenolides by an Ivanov Reaction/Silver(I)-Catalyzed Lactonization/In Situ Dehydration Sequence
复制标题
通过 Ivanov 反应/银 (I) 催化内酯化/原位脱水序列两步合成 (Z)-3-芳基-5-(芳基亚甲基)丁烯内酯
DOI：
10.1055/s-0036-1588338
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
R. Brückner
中科院分区：
文献类型：
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作者：
D. Hermann;D. Arican;R. Brückner
报道了标题化合物的立体选择性合成方法。将α-锂化芳基乙酸锂（“芳基乙酸二阴离子”）的无己烷和无胺的THF溶液羟醛加成到3-芳基丙炔醛中。这得到2，5-二芳基-3-羟基戊-4-炔酸，其对反式非对映异构体的优选性高达72：28（27个实施例+1个例外）。当在室温下用DMF中的Ag 2CO 3（1-20摩尔%）处理2.5天时，相应的混合物经历区域选择性和立体选择性内酯化，然后原位脱水。由此得到3-芳基-5-（芳基亚甲基）丁烯内酯，其含氧C=C键为aZ-构型。其总收率范围为46%至83%（1个例外：28%）。三个3-芳基-5-（芳基亚甲基）丁烯内酯含有C-Br和/或C-I键。它们允许随后的Pd催化的C-C偶联，其提供后续丁烯内酯。
A stereoselective synthesis of the title compounds was developed. Hexane- and amine-free THF solutions of α-lithiated lithium arylacetates (‘arylacetic acid dianions’) were aldol-added to 3-arylpropynals. This gave 2,5-diaryl-3-hydroxypent-4-ynoic acids with up to a 72:28 preference for theanti-diastereomer (27 examples + 1 exception). When treated with Ag2CO3(1–20 mol%) in DMF at room temperature for 2.5 days, the respective mixtures underwent regio- and stereoselective lactonizations followed by an in situ dehydration. Thereby 3-aryl-5-(arylmethylidene)butenolides were obtained with aZ-configuration of the oxygenated C=C bond. Their overall yields ranged from 46% to 83% (1 exception: 28%). Three 3-aryl-5-(arylmethylidene)butenolides contained a C–Br and/or a C–I bond. They allowed a subsequent Pd-catalyzed C–C coupling, which furnished follow-up butenolides.