Nucleophilic deoxyfluorinalton of one of the two hydroxyl groups of catechols has been developed via the Umpolung concept. This method was successively applied to naturally occurring catechols, such as catechins and dopamine, to produce novel fluorinated analogues.
Efficient and Practical One-Pot Conversions of N-Tosyltetrahydroisoquinolines into Isoquinolines and of N-Tosyltetrahydro-β-carbolines into β-Carbolines through Tandem β-Elimination and Aromatization
An efficient, practical, and general method for conversions of N-tosyltetrahydroisoquinolines (N-tosyl-THIQs) into isoquinolines and of N-tosyltetrahydro-β-carbolines (N-tosyl-THBCs) into β-carbolines is described. Treatment of N-tosyl-THIQs or N-tosyl-THBCs with base in dimethyl sulfoxide afforded dihydroisoquinolines or dihydro-β-carbolines as intermediates, and these were then oxidized in situ by
Synthesis of 1,2,3,4‐Tetrahydroisoquinolines via Palladium‐Catalyzed Cyclization of
<i>N</i>
‐Tosylhydrazones with
<i>ortho</i>
‐Bromophenethyl Tosylamides
A Pd-catalyzed synthesis of 1,2,3,4-tetrahydroisoquinoline (THIQ) via cyclization of ortho-bromophenethyl tosylamides with aryl N-tosylhydrazones in the presence of base was developed. The reaction is believed to proceed via the oxidative addition of palladium with ortho-bromophenethyl tosylamides, followed by carbene insertion and cyclization. The carbene species were generated in-situ from the aryl
开发了一种 Pd 催化合成 1,2,3,4-四氢异喹啉 (THIQ),方法是在碱存在下邻溴苯乙基甲苯磺酰胺与芳基N-甲苯磺酰腙环化。据信该反应是通过钯与邻-溴苯乙基甲苯磺酰胺的氧化加成反应进行的,然后是卡宾插入和环化。卡宾物种由芳基N-甲苯磺酰腙和 KO t Bu 原位生成。
Thiophenol-mediated improvement of the Pictet–Spengler cyclization of N-tosyl-β-phenethylamines with aldehydes
作者:Claudio C. Silveira、Adriano S. Vieira、Teodoro S. Kaufman
DOI:10.1016/j.tetlet.2006.08.097
日期:2006.10
The Lewis acid-catalyzed Pictet-Spengler condensation of N-tosyl-beta-phenethylamines with aldehydes is improved by the addition of thiophenol, furnishing better yields of 1-substituted tetrahydroisoquinolines at a given time. (c) 2006 Elsevier Ltd. All rights reserved.