TfNHNHBoc as a Trifluoromethylating Agent for Vicinal Difunctionalization of Terminal Alkenes

Abstract

An unprecedented application of trifluoromethanesulfonyl hydrazides as trifluoromethylating agents has been demonstrated in two vicinal difunctionalization reactions of terminal alkenes: the copper-catalyzed three-component vicinal chlorotrifluoromethylation of arylakenes with TfNHNHBoc and NaCl and the tandem trifluoromethylation/cyclization of N-arylacrylamides with TfNHNHBoc. The reactions proceeded in the presence of inexpensive oxidants under mild conditions and provided a range of structurally diverse trifluoromethyl-containing compounds with high regioselectivity.

Sulfonyl Hydrazides in Organic Synthesis: A Review of Recent Studies

“…The Tian group reported the application of TfNHNHBoc as a trifluoromethylating reagent in difunctionalizations of terminal alkenes (Eq. 50‐1,2).…”

Visible‐Light‐Induced Three‐Component Intermolecular Trifluoromethyl‐Alkenylation Reactions of Unactivated Alkenes

“…Over the past few decades, a number of methods for alkene difunctionalization have been developed, including transition‐metal‐catalyzed reactions, visible‐light‐mediated reactions, reactions involving both photoredox and transition‐metal catalysts, and electrocatalytic fluoroalkylation reactions [4] . Of these methods, one of the most attractive involves difunctionalization of alkenes with CF 3 radical (such as the Umemoto reagent, [5] Togni reagents, [6] Langlois’ reagent, [7] CF 3 SO 2 Cl, [8] CF 3 I, [9] CF 3 Br, [10] TMSCF 3 , [11] CF 3 SO 2 NHNHBoc, [12] (CF 3 CO) 2 O [13] and (bpy)Cu(CF 3 ) 3 [14] ) (Scheme 1A). Using these reagents, many research groups have achieved various difunctional modifications of the styrenes and unactivated alkenes through trifluoromethyl radicals.…”

Electrochemical Difluoromethylation of Electron‐Deficient Alkenes

“…Although an ester reacted to afford the difunctionalization product ( 22 ) in moderate yield (38 %), the corresponding free carboxylic acid failed completely ( 23 ). Hydroxytrifluoromethylation could also be achieved by using CF 3 SO 2 NHNHBoc as the CF 3 source ( 24 ).…”