Synthesis of 4-arylcoumarins via palladium-catalyzed arylation/cyclization of ortho-hydroxylcinnamates with diaryliodonium salts
作者:Yang Yang、Jianwei Han、Xunshen Wu、Shujia Xu、Limin Wang
DOI:10.1016/j.tetlet.2015.04.082
日期:2015.6
ortho-hydroxylcinnamate ester derivatives by using diaryliodonium(III) salts has been developed. With this method, 4-arylcoumarins were easily prepared in good to excellent yields under base-free conditions. Additionally, this protocol provided an efficient alternative for the preparation of related 4-arylated coumarin compounds which are useful in the access to 5-lipoxygenaseinhibitors.
An enhanced stereoselective synthesis of α,β-unsaturated esters through the Horner–Wadsworth–Emmons reaction in deep eutectic solvents
作者:Andrea Nicola Paparella、Margherita Stallone、Mara Pulpito、Filippo Maria Perna、Vito Capriati、Paola Vitale
DOI:10.1039/d3ob02083e
日期:——
A new scalable synthesis of (E)-α,β-unsaturated esters has been developed using protic, non-toxic, and biodegradable deep eutectic solvents through the Horner–Wadsworth–Emmons reaction between triethyl phosphonates and (hetero)aromatic carbonyl compounds, encompassing electron-withdrawing and electron-donating groups. Stereoselective preparation of disubstituted or trisubstituted ethyl cinnamate derivatives
通过膦酸三乙酯和(杂)芳族羰基化合物之间的霍纳-沃兹沃斯-埃蒙斯反应,使用质子、无毒且可生物降解的低共熔溶剂开发了一种新的可规模合成( E )-α,β-不饱和酯,包括吸电子基团和给电子基团。在LiOH、K 2 CO 3或DBU作为碱的存在下,在室温和空气下实现二取代或三取代的肉桂酸乙酯衍生物的立体选择性制备。通过 ( E )-3-(4-溴苯基)丙烯酸乙酯的合成证明,相同的低共熔混合物(氯化胆碱/尿素)被证明可在连续三次运行中重复使用。可以进行克级反应(10 mmol)而不会形成副产物,从而确保高原子经济性和EcoScale评分为71。
Visible-Light-Driven, Photoredox-Catalyzed Cascade of <i>ortho-</i>Hydroxycinnamic Esters To Access 3-Fluoroalkylated Coumarins
作者:Dan Song、Chao-Ming Wang、Zhi-Peng Ye、Peng-Ju Xia、Zhi-Xiong Deng、Jun-An Xiao、Hao-Yue Xiang、Hua Yang
DOI:10.1021/acs.joc.9b00715
日期:2019.6.7
A general and straightforward protocol for di-/perfluoroalkylation of ortho-hydroxycinnamic esters via a photoredox-catalyzed cascade was developed to access a variety of 3-fluoroalkylated coumarins. This method was characterized by all-in-one synthetic design, simplified operation, mild reaction conditions, and broad substrate scope. Moreover, a sequential one-pot procedure starting from commercially available salicylaldehyde was also successfully realized to synthesize 3-fluoroalkylated coumarins.
Visible-Light-Driven, Photocatalyst-Free Cascade to Access 3-Cyanoalkyl Coumarins from <i>ortho</i>-Hydroxycinnamic Esters
Palladium catalyzed Heck-arylation/cyclization cascade: An environmentally benign and efficient synthesis of 4-arylcoumarins in water
作者:Junmin Chen、Wei Liu、Liandi Zhou、Yongli Zhao
DOI:10.1016/j.tetlet.2018.05.032
日期:2018.6
An environmentally benign and efficient approach for the synthesis of 4-arylcoumarins from ortho-hydroxy cinnamate ester derivatives with aryl iodides was developed in water under aerobic conditions. This transformation proceeds through a palladiumcatalyzed Heck-arylation/cyclization cascade reaction. The present protocol features a wide substrate scope and readily available starting materials to