Palladium and Nickel-Catalyzed Perfluoroalkylation of Aldehydes Using Zinc and Perfluoroalkyl Halides

Abstract

A room temperature method for the conversion of perfluoroalkyl iodides to α-perfluoroalkyl carbinols under Pd or Ni catalysis is reported. The use of trifluoromethyl bromide provides an economical procedure for trifluoromethyl substituted carbinols.

Introduction of Fluorine and Fluorine‐Containing Functional Groups

“…Perfluoroalkyl transition metal complexes can react with alkynes,433 dienes, and allylic halides,434 as well as propargyl halides435 to afford the corresponding perfluoroalkylated alkenes and allenes. Nucleophilic reagents, such as perfluoroalkyl lithium,436 ‐magnesium bromide,437 calcium,438 tin,439 trimethylsilane440 and zinc (with a palladium or nickel catalyst),434, 441 were used prior to the development of the TDAE/perfluoroalkyl halide combination by Dolbier and co‐workers, which is a straightforward and practical method for the perfluoroalkylation of aldehydes, ketones, imines, disulfides, and diselenides (Scheme ),442 and affords nonafluorobutylation products in 20–98 % yield. Similarly, Prakash et al.…”

Preparation of α,β-Unsaturated Ketones Bearing a Trifluoromethyl Group and Their Application in Organic Synthesis

“…Secondary carbinols, obtained by the addition of vinyl organometallics to trifluoroacetaldehyde [59] or perfluoroalkyl organometallics to unsaturated aldehydes (Scheme 22) [60][61][62] can be oxidized by Dess-Martin [63,64] or Swern [65] reagents or using MnO 2 [66] in dichloromethane to the α,β-ethylenic trifluoromethyl ketones in good yields. [66,67] It should be noted that the reduction of acetylenic CF 3 ketones using LiAlH 4 or NaBH 4 does not give CF 3 enones but the corresponding allyl alcohols [50,64,68].…”

Einführung von Fluor und fluorhaltigen funktionellen Gruppen

“…[296b] Sanford berichtete über die Perfluoralkylierung von Arenen mit einem Palladium-BINAP-Katalysator und Perfluoralkylhalogenid, bei der das Aren in Lçsungsmittelmengen eingesetzt wird (Schema 101). Nucleophile Reagentien wie die Perfluoralkylderivate von Lithium, [436] Magnesiumbromid, [437] Calcium, [438] Zinn, [439] Trimethylsilan [440] und Zink (mit einem Palladium-oder Nickelkatalysator) [434,441] wurden verwendet, bevor Dolbier et al TDAE/Perfluoralkylhalogenid als Reagens zur direkten und zweckmäßigen Perfluoralkylierung von Aldehyden, Ketonen, Iminen, Disulfiden und Diseleniden entwickelten (Schema 102), [442] das nonafluorbutylierte Produkte in 20-98 % Ausbeute liefert. [432] Perfluoralkylübergangsmetallkomplexe reagieren mit Alkinen, [433] Dienen und Allylhalogeniden [434] sowie Propargyl- halogeniden [435] zu den entsprechenden perfluoralkylierten Alkenen und Allenen.…”