Removal of Fluorine from and Introduction of Fluorine into Polyhalopyridines: An Exercise in Nucleophilic Hetarenic Substitution
作者:Carla Bobbio、Thierry Rausis、Manfred Schlosser
DOI:10.1002/chem.200400837
日期:2005.3.4
Starting from six industrially available fluorinated pyridines, an expedient access to all three tetrafluoropyridines (2-4), all six trifluoropyridines (5-10), and the five non-commercial difluoropyridines (11-14 and 16) was developed. The methods employed for the selective removal of fluorine from polyfluoropyridines were the reduction by metals or complex hydrides and the site-selective replacement
从六个工业上可获得的氟化吡啶开始,开发了一种方便的途径来获取所有三个四氟吡啶(2-4),所有六个三氟吡啶(5-10)和五个非商业性二氟吡啶(11-14和16)。用于从多氟吡啶中选择性除去氟的方法是通过金属或复合氢化物进行还原,并用肼进行位点选择性置换,然后进行脱氢-脱重氮或脱氢氯化-脱重氮。为了引入额外的氟原子,在进行氯/氟置换过程之前,将合适的前体金属化和氯化。