Silver(I)‐Catalyzed N‐Trifluoroethylation of Anilines and O‐Trifluoroethylation of Amides with 2,2,2‐Trifluorodiazoethane

Abstract

A straightforward N-trifluoroethylation of anilines has been developed based on silver-catalyzed N-H insertions with 2,2,2-trifluorodiazoethane (CF3CHN2). Mechanistically, the reaction is proposed to involve migratory insertion of a silver carbene as the key step. In contrast, when amides are employed as the substrates under similar reaction conditions, O-trifluoroethylation occurs to afford trifluoroethyl imidates.

Copper‐Catalyzed Insertion into Heteroatom–Hydrogen Bonds with Trifluorodiazoalkanes

“…A catalyst loading of 2mol %w as effective,b ut the product was formed in lower yield when it was decreased to 1mol % ( Table 1, entries 7and 9). [9] As expected, the catalyst was essential for SiÀHi nsertion (Table 1, entry 11). No reaction took place with AgSbF 6 (5 mol %) in 1,2-dichloroethane (DCE;T able 1, entry 10);t hese reaction conditions were identified as optimal for the N-trifluoroethylation of anilines and amides.…”

“…With heteroatom functionalization as our primary objective,w eo pted to address this problem with as trategy based on heteroatom-hydrogen bond (X À H) insertion. [9] Herein, we report that Si À H, B À H, P À H, S À H, and N À Hinsertion reactions of trifluorodiazoalkanes are possible under Cu I catalysis;a symmetric variants are reported for selected SiÀHand BÀHinsertions.The insertion products expand the chemical space available to chemists (Scheme 1B). [6] This methodology has been studied extensively with a-diazoesters and a-diazoketones, and extended to numerous asymmetric carbene-insertion reactions.T he attractive synthetic route towards 2,2,2-trifluorodiazoethane (CF 3 CHN 2 )r eported by Morandi and Carreira [7] led us to consider this class of CF 3 -containing synthon in the context of XÀHi nsertion.…”

Copper‐Promoted Ritter‐Type Trifluoroethoxylation of (Hetero)arenediazonium Tetrafluoroborates: A Method for the Preparation of Trifluoroethyl Imidates

“…Another commonly used strategy involves the reaction of imidoyl chlorides and NaOCH 2 CF 3 (Scheme , b), which suffers from the unavailability of imidoyl chlorides. Recently, Wang and co‐workers reported a novel method for the silver‐catalyzed trifluoroethylation of amides with CF 3 CHN 2 to afford trifluoroethyl imidates (Scheme , c) . This O ‐selective trifluoroethylation protocol contrasts the normal N ‐trifluoroethylation of amides with CF 3 CH 2 I or CF 3 CH 2 OMs (Ms = methylsulfonyl) .…”

“…Recently, Wang and co-workers reported a novel method for the silver-catalyzed trifluoroethylation of amides with CF 3 CHN 2 to afford trifluoroethyl imidates (Scheme 1, c). [12] This O-selective trifluoroethylation protocol contrasts the normal N-trifluoroethylation of amides with CF 3 CH 2 I or CF 3 CH 2 OMs (Ms = methylsulfonyl). [13] Despite the above achievements, there still remains a need for new synthetic methods of trifluoroethyl imidates starting from readily available materials under mild conditions.…”

Silver-Catalyzed Cyclopropanation of Alkenes Using N-Nosylhydrazones as Diazo Surrogates

“…Based on the experimental results and relatedp recedents, [28] we suggestap resumed mechanistic description for the silvercatalyzed cyclopropenation reactiono fa lkynes with non-stabilized diazoalkanes (Scheme 5). Base-promoted dissociation of N-nosylhydrazones 1 first occurs to generate unstabled iazo compound A,w hichr eadily undergoes dinitrogen extrusion by asilver catalysttogive at ransient silver carbenoid B.…”