在铁粉存在下,以商用N,N-二甲基甲酰胺(DMF)作溶剂,90℃、氮气保护下,二芳基二硒醚与α-溴代羰基化合物反应,得到一系列α-芳硒基羰基化合物.考察了温度、时间、溶剂及铁粉用量对反应的影响,其中,温度对反应的影响最为明显.α-溴代羰基...在铁粉存在下,以商用N,N-二甲基甲酰胺(DMF)作溶剂,90℃、氮气保护下,二芳基二硒醚与α-溴代羰基化合物反应,得到一系列α-芳硒基羰基化合物.考察了温度、时间、溶剂及铁粉用量对反应的影响,其中,温度对反应的影响最为明显.α-溴代羰基化合物中羰基上取代基对反应有很大影响,取代基为苯基时,转化率较甲基或烷氧基时低.反应机理可能是铁插入Se—Se键中形成亲核性Se Fe Se,随后与亲电底物α-溴代羰基化合物发生亲核取代.本方法使用铁粉促进断裂Se—Se键具有原料安全无毒、廉价易得、实验操作简便等优点.展开更多
Asymmetric electrochemical synthesis has emerged as an attractive and sustainable alternative for the distinctive activation of bond connections in the preparation of diverse enantiomerically enriched targets,includin...Asymmetric electrochemical synthesis has emerged as an attractive and sustainable alternative for the distinctive activation of bond connections in the preparation of diverse enantiomerically enriched targets,including natural products and pharmaceutical agents.Herein,we describe the chiral Lewis acid-catalyzed enantioselective electrochemical anodic coupling reaction as a key step in the presented formal synthesis of isopavine alkaloids.展开更多
报道了手性膦烯配体在金属铑催化的芳基硼酸对β-芳基-α,β-不饱和磺酸酯不对称共轭加成中的应用.经过系统的反应条件筛选和配体结构优化,发现含手性1,1'-联-2-萘酚骨架的膦烯配体L7与Rh(I)形成的催化剂可以高对映选择性地实现β-...报道了手性膦烯配体在金属铑催化的芳基硼酸对β-芳基-α,β-不饱和磺酸酯不对称共轭加成中的应用.经过系统的反应条件筛选和配体结构优化,发现含手性1,1'-联-2-萘酚骨架的膦烯配体L7与Rh(I)形成的催化剂可以高对映选择性地实现β-芳基-α,β-不饱和磺酸酯化合物的不对称1,4-加成反应.此反应体系条件温和,底物普适性广,并取得了较高的收率(up to 95%)和优秀的对映选择性(up to 99%ee),为合成手性偕二芳基取代的磺酸酯类化合物提供了一种新方法.展开更多
文摘在铁粉存在下,以商用N,N-二甲基甲酰胺(DMF)作溶剂,90℃、氮气保护下,二芳基二硒醚与α-溴代羰基化合物反应,得到一系列α-芳硒基羰基化合物.考察了温度、时间、溶剂及铁粉用量对反应的影响,其中,温度对反应的影响最为明显.α-溴代羰基化合物中羰基上取代基对反应有很大影响,取代基为苯基时,转化率较甲基或烷氧基时低.反应机理可能是铁插入Se—Se键中形成亲核性Se Fe Se,随后与亲电底物α-溴代羰基化合物发生亲核取代.本方法使用铁粉促进断裂Se—Se键具有原料安全无毒、廉价易得、实验操作简便等优点.
基金The authors acknowledge financial support from the National Natural Science Foundation of China(grant nos.21702198 and 21971227)the Anhui Provincial Natural Science Foundation(grant no.1808085MB30)the Fundamental Research Funds for the Central Universities(no.WK2340000090).
文摘Asymmetric electrochemical synthesis has emerged as an attractive and sustainable alternative for the distinctive activation of bond connections in the preparation of diverse enantiomerically enriched targets,including natural products and pharmaceutical agents.Herein,we describe the chiral Lewis acid-catalyzed enantioselective electrochemical anodic coupling reaction as a key step in the presented formal synthesis of isopavine alkaloids.
文摘报道了手性膦烯配体在金属铑催化的芳基硼酸对β-芳基-α,β-不饱和磺酸酯不对称共轭加成中的应用.经过系统的反应条件筛选和配体结构优化,发现含手性1,1'-联-2-萘酚骨架的膦烯配体L7与Rh(I)形成的催化剂可以高对映选择性地实现β-芳基-α,β-不饱和磺酸酯化合物的不对称1,4-加成反应.此反应体系条件温和,底物普适性广,并取得了较高的收率(up to 95%)和优秀的对映选择性(up to 99%ee),为合成手性偕二芳基取代的磺酸酯类化合物提供了一种新方法.