Improved Preparation of Tertiary Chlorides by Halodecarboxylation

Decarboxylative Halogenation of Organic Compounds

“… 145 , 146 Attempts to perform the chlorodecarboxylation of aromatic acids by either the Kochi or Grob approach failed or provided negligible yields. 113 , 114 , 118 , 147 Therefore, we can conclude that this reaction is, most likely, not a method of choice for the preparation of aryl halides.…”

“…Tertiary alkyl chlorides are obtained in significantly lower yields, especially on a large scale. 118 The problem with the preparation of tertiary chlorides was addressed by Grob and co-workers. 118 The use of N -chlorosuccinimide (NCS) as a source of the chlorine atom instead of LiCl, and applying a DMF/acetic acid solvent system, made the preparation of various non-bridgehead tertiary alkyl chlorides possible.…”

“… 118 The problem with the preparation of tertiary chlorides was addressed by Grob and co-workers. 118 The use of N -chlorosuccinimide (NCS) as a source of the chlorine atom instead of LiCl, and applying a DMF/acetic acid solvent system, made the preparation of various non-bridgehead tertiary alkyl chlorides possible. It allowed the chlorodecarboxylation to be performed at lower temperatures (compared to the original process), enabling the synthesis of a number of heat-sensitive tertiary chlorides in reasonable yields ( Scheme 24 ).…”

“…Unlike the Hunsdiecker and Cristol–Firth reactions, the process is not restricted to bridgehead tertiary carboxylic acids, although the yields of tertiary chlorides are relatively low. 118 The aforementioned Grob modification allows the preparation of sensitive non-bridgehead tertiary alkyl chlorides in good to excellent yields. The Barton approach can furnish tertiary alkyl iodides, although in very low yields.…”

“…The original Kochi procedure is suitable for the preparation of primary and secondary alkyl chlorides. Tertiary alkyl chlorides are obtained in significantly lower yields, especially on a large scale . The problem with the preparation of tertiary chlorides was addressed by Grob and co-workers .…”