Iron‐Catalyzed 1,2‐Addition of Perfluoroalkyl Iodides to Alkynes and Alkenes

Abstract

Iron catalysis has been developed for the intermolecular 1,2‐addition of perfluoroalkyl iodides to alkynes and alkenes. The catalysis has a wide substrate scope and high functional‐group tolerance. A variety of perfluoroalkyl iodides including CF3I can be employed. The resulting perfluoroalkylated alkyl and alkenyl iodides can be further functionalized by cross‐coupling reactions. This methodology provides a straightforward and streamlined access to perfluoroalkylated organic molecules.

Copper‐Catalyzed Difunctionalization of Activated Alkynes by Radical Oxidation–Tandem Cyclization/Dearomatization to Synthesize 3‐Trifluoromethyl Spiro[4.5]trienones

“…In 2012, copper‐catalyzed oxytrifluoromethylation of terminal alkynes was reported by the groups of Szabó9e and Sodeoka9f independently. Recently, Hu and co‐workers described an iron‐catalyzed iodotrifluoromethylation of terminal alkynes using CF 3 I as the CF 3 source 9i. Similarly, Cho and co‐workers disclosed the iodotrifluoromethylation of terminal alkynes by visible‐light photoredox catalysis 9h.…”

Nickel‐Catalyzed C–H Trifluoromethylation of Electron‐Rich Heteroarenes

“…radicals, the reduction of trifluoromethyl iodide (iodotrifluoromethane, ICF 3 ), a commercially available and relatively inexpensive industrial raw material, has emerged as an efficient and economic path, and many initiator systems to generate CF 3 . from CF 3 I were subsequently reported, for example, Ir or Ru photocatalysts,,, Et 3 B/O 2 , Pd, Ag, Fe,, and free metals…”

Copper‐Catalyzed 1,2‐Addition of α‐Carbonyl Iodides to Alkynes

“…However, no product was formed using the conditions previously developed for Fe-catalyzed perfluoroalkylation ( Table 1, entry 1). [8] A screening of catalysts (see Supporting Information) showed that Cu(OTf) 2 in combination with ligand II could catalyze this reaction in toluene in a 57 % yield (entry 2). Replacement of Cu(OTf) 2 by other copper salts led to lower yields (entries 3 and 4).…”

“…Cs 2 CO 3 is able to generate the alkyl radical from activated alkyl halides at an elevated temperature. [8] The mechanism of the a-alkenylation reaction is subject to further study, so only a hypothetical catalytic cycle is proposed here based on the above results (Scheme 5). The reaction starts from the in situ generation of an a-iodo ketone from the reaction of the a-bromo ketone with KI.…”