A detailed mechanism illustrating demethylation of methyl ethers using boron tribromide (BBr3).

To a suspension of the SM (1.26 g, 4.6 mmol) in DCM (20 mL) at 0 C was added dropwise BBr3 (1M in DCM, 28 mL, 28 mmol). The reaction was stirred at 45 C overnight. The mixture was concentrated to dryness, cooled in an ice bath, and diluted with sat aq NaHCO3. The resulting solids were collected and air dried to provide impure product which was ...

Boron tribromide, BBr 3, is a colorless, fuming liquid compound containing boron and bromine. Commercial samples usually are amber to red/brown, due to weak bromine contamination. It is decomposed by water and alcohols. [2] Boron tribromide is commercially available and is …

2016年7月15日 · 有机合成中经常碰到酚羟基的保护与脱保护，使用甲基作为酚羟基的保护基比较常见，形成甲基芳基醚，再经过脱甲基化还原出酚羟基。 一般脱甲基试剂的种类可以分为： 1，酸性脱甲基试剂. 2，碱性脱甲基试剂. 3，其他条件脱甲基试剂. 常见的酸性脱甲基试剂有三溴化硼、三氯化铝、氢溴酸、硫酸等。 以三溴化硼为例： 反应机理. 主要利用B的亲电性和Br的亲核性,常用的溶剂为二氯甲烷。 反应实例[1] 若芳基甲醚除甲氧基外其他结构对碱不敏感，对酸敏感。 可 …

2015年10月23日 · One of the most well-known, highly utilized reagents for ether cleavage is boron tribromide (BBr 3), and this reagent is frequently employed in a 1:1 stoichiometric ratio with ethers. Density functional theory calculations predict a new mechanistic pathway involving charged intermediates for ether cleavage in aryl methyl ethers.

2013年5月31日 · Secondary and tertiary alkyl ethers are cleaved through Br – transfer from the activated BBr 3 to the alkyl moiety, whereas other ethers react through a bimolecular mechanism involving two adducts, one of which acts as Br – donor, and the second as the reaction substrate.

We recommend the use of at least 1 cquiv of BBr3 for each MeO group or other group containing an "electron-donor" element, e.g. 3 equivs for a compound containing two McO and one CN group. 3.5-Dihydroxybenzyl cyanide.

2015年10月23日 · 三溴化硼 (BBr3) 是最广为人知、使用率最高的醚裂解试剂之一，该试剂通常与醚以 1:1 的化学计量比使用。 密度泛函理论计算预测了一种新的机械途径，涉及芳基甲基醚中醚裂解的带电中间体。

BBr3是一种温和、优良的去甲基化试剂，并且不影响 分子中的酯基和双键，在许多天然产物的全合成中常 使用它。 一般使用CH2Cl2, benzene, pentane作为溶剂，在-78 ℃到室温下进行。

三溴化硼，是一种无机化合物，化学式为BBr3，是Lewis酸，为无色透明液体，溶于四氯化碳、二氧化硫（液体）、二硫化碳，主要用于有机硼化合物和高纯硼的制取，也用作半导体的掺杂材料，还可用作有机合成的催化剂、溴化剂等。