Synthetic Approach to Benzocyclobutenones Using Visible Light and a Phosphonate Auxiliary
摘要:
Reported herein is a two-step procedure to synthesize benzocyclobutenones from (o-alkylbenzoyl)-phosphonates. It consists of a visible-light-driven cyclization reaction forming phosphonate-substituted benzocyclobutenols and subsequent elimination reaction of the H-phosphonate, which assumes a key role as the recyclable auxiliary. A wide variety of functionalized benzocyclobutenones, which include those difficult to synthesize by conventional methods, are efficiently synthesized.
Highly diastereoselective vinylogous Mukaiyama aldol reaction of α-keto phosphonates with 2-(trimethylsilyloxy)furan catalyzed by Cu(OTf)2
作者:Jipan Yu、Xiaona Zhao、Zhiwei Miao、Ruyu Chen
DOI:10.1039/c1ob05822c
日期:——
achieved via a vinylogous Mukaiyamaaldolreaction. The reaction was performed using α-ketophosphonate 1 and 2-(trimethylsilyloxy)furan 2 mediated by Cu(OTf)2 and 2,2,2-trifluoroethanol as additive in CH2Cl2. The reaction proceeds rapidly and affords the corresponding 5-(hydroxy(aryl)methyl) furan-2(5H)-one phosphonates 3 in high yields with good to excellent diastereoselectivities (d.r. up to >99 : 1)
Enantio- and Diastereoselective Vinylogous Mukaiyama Aldol Reactions of α-Keto Phosphonates with 2-(Trimethylsilyloxy)- furan Catalyzed by Bis(oxazoline)-Copper Complexes
The asymmetric vinylogousMukaiyamaaldolreaction between α-keto phosphonate and 2-(trimethylsilyloxy)furan was performed by using bis(oxazoline)-copper complexes as the catalyst and 2,2,2-trifluoroethanol as additive in dichloromethane. The present method is highly tolerable for functionalized α-keto phosphonates and enabled us to obtain the corresponding 3- and 4-substituted benzyl-functionalized
Highly efficient and selective olefination of acyl phosphonates with ethyl diazoacetate catalyzed by a cobalt(II) porphyrin complex
作者:Erkan Ertürk、Ayhan S. Demir
DOI:10.1016/j.tet.2008.05.108
日期:2008.8
The cobalt(II) porphyrin complex (CoTPP) was found to be an efficient catalyst for the Wittig type olefination of acyl phosphonates with ethyl diazoacetate (EDA) in the presence of triphenylphosphine (Ph3P). By using this one pot methodology under mild conditions, densely functionalized vinyl phosphonates were obtained in high yields and high E/Z selectivities in relatively short reaction times. A rather
allowing effective control of the end of the reaction and identification of all phosphorylated intermediate species, which enabled us to propose a reaction mechanism. Optimized experimental conditions were applied to the preparation of biological relevant aminoalkyl-HMPPs. A preliminary study of the complexation to hydroxyapatite (bone matrix) was carried out in order to verify its lower affinity towards
Direct and safe one-pot synthesis of functionalized dimethyl 1-aryl-1,9a-dihydropyrido[2,1-c][1,4]thiazine-1-phosphonates
作者:Yuliang Wei、Simin Sun、Jiaxi Xu
DOI:10.1016/j.tetlet.2023.154444
日期:2023.3
A visible-light-induced direct and safe synthesis of functionalized dimethyl 1-aryl-1,9a-dihydropyrido[2,1-c][1,4]thiazine-1-phosphonates is realized from dimethyl (aryl(2-tosylhydrazono)methyl)phosphonates and pyridinium 1,4-zwitterionic thiolates with cesium carbonate as base in dichloromethane. The reaction involves the carbene generation from dimethyl (aryl(2-tosylhydrazono)methyl)phosphonates
可见光诱导的功能化二甲基 1-aryl-1,9a-二氢吡啶并 [2,1- c ][1,4]thiazine-1-phosphonates 的直接和安全合成是从二甲基 (aryl(2-tosylhydrazono)甲基)膦酸盐和吡啶 1,4-两性离子硫醇盐,以碳酸铯为碱,溶于二氯甲烷。该反应涉及在碳酸铯作为碱存在下,从二甲基(芳基(2-甲苯磺酰亚肼基)甲基)膦酸酯生成卡宾,以及卡宾与吡啶 1,4-两性离子硫醇盐发生 [1+5] 环化以合成功能化的 1, 9a-二氢吡啶并[2,1- c ][1,4]噻嗪衍生物。该方法避免了制备、储存和使用具有潜在危险的磷酰基重氮化合物,具有简便、无催化剂、反应条件温和的特点。