First example of base-promoted tandem alkylation–bromination of 2-bromothiophene via halogen dance process: a remarkable temperature effect
摘要:
Metalation-alkylation of 2-bromothiophene 1 when conducted at low temperature led to the 5-alkylated 2-bromo products 2. While, at room temperature, the same sequential reactions afforded the original dibrorno-alkylated thiophenes 3 following an unprecedented halogen transfer-based halogen dance process in highly regiocontrolled and ordered way. (c) 2005 Elsevier Ltd. All rights reserved.
Disproportionation reaction of diarylmethylisopropyl ethers: a versatile access to diarylmethanes from diarylcarbinols speeded up by the use of microwave irradiation
An efficient synthesis of diarylmethanes under classical thermal conditions and under microwave heating is described fromdiarylcarbinols via a new disproportionation reaction. The key step involves a selective hydride transfer of isopropyl ether intermediates. Mild reaction conditions i.e., catalytic CBr4 or TfOH in i-PrOH and good yields render this method useful and competitive to the conventional
First example of base-promoted tandem alkylation–bromination of 2-bromothiophene via halogen dance process: a remarkable temperature effect
作者:Corinne Peyron、Jean-Michel Navarre、Nathalie Van Craynest、Rachid Benhida
DOI:10.1016/j.tetlet.2005.03.109
日期:2005.5
Metalation-alkylation of 2-bromothiophene 1 when conducted at low temperature led to the 5-alkylated 2-bromo products 2. While, at room temperature, the same sequential reactions afforded the original dibrorno-alkylated thiophenes 3 following an unprecedented halogen transfer-based halogen dance process in highly regiocontrolled and ordered way. (c) 2005 Elsevier Ltd. All rights reserved.