本文中,我们报告了使用β-羰基苯并噻唑(BT)砜中间体通过Mitsunobu反应将1°和2°醇有效地一碳和二碳同系化为它们相应的同系酯。一碳同系物方法使用标准的Mitsunobu C–S键形成,氧化和随后的烷基化,而二碳同系物使用较少见的CC碳键形成Mitsunobu反应。在后一种情况下,使用含β-BT砜的酯会降低p K a足以将底物用作基于碳的亲核试剂并传递同源的β-BT砜酯,然后可以裂解该多余的砜基。在本文中,我们描述了几种有效进行BT砜脱磺酰化的方法,并开发了用于一锅烷基化脱磺酰化序列的方法。因此,总的来说,可以通过两锅法(四步法)实现一碳同源序列,而通过两锅法(三步法)(三锅;在C-包括酸合成)。该方法学已被应用于多种功能(酯,甲硅烷基醚,苄基,杂芳基,酮,烯烃和炔烃),并且均能很好地耐受,从而提供了很好的总收率。
Practical Synthesis of β-Acyl and β-Alkoxycarbonyl Heterocyclic Sulfones
摘要:
A short and efficient synthesis for beta-acyl and beta-alkoxycarbonyl heterocyclic sulfones containing benzothiazol (BT) and phenyltetrazol (PT) heterocydic core is presented here. The method seems to be general and provides the desired C-nudeophiles in very good to excellent yields from readily available starting materials.
On the Origin of<i>E</i>/<i>Z</i>Selectivity in the Modified Julia Olefination - Importance of the Elimination Step
作者:Raphaël Robiette、Jiří Pospíšil
DOI:10.1002/ejoc.201201634
日期:2013.2
The mechanism and origin of high E selectivity in the modifiedJuliaolefination of aromatic aldehydes have been explored by computational and experimental means. Reversibility of addition and hence selectivity of the formation of sulfinate 5 is very variable and depends on the nature of the sulfone substrate. However, in all cases, elimination occurs through a concerted antiperiplanar and synperiplanar
In this paper, we discuss our new synthetic approach towards functionalized benzo[d]thiazolyl (BT) sulfones, based on the reunion of alkyl BT sulfones and various electrophiles (e.g. RâCOâX, ROâCOâX, RSâCOâX, TsâXâ¦). All important aspects of this coupling reaction, including relevant and undesirable side reactions, are evaluated by means of calculations and competitive experiments. The scope and limitations of this method are established.