Ligand-dependent stereoselective Suzuki–Miyaura cross-coupling reactions of β-enamido triflates

Abstract

The stereoselective Suzuki–Miyaura cross-coupling of (Z)-β-enamido triflates is demonstrated. Depending on the nature of the ligand in the palladium catalyst, either retention or inversion of the configuration during the synthesis of β,β-diaryl-substituted enamides is observed. Thus, the method provides synthetic access to both isomers of the target enamides from (Z)-β-enamido triflates.

Recent Advances in Pd‐Catalyzed Suzuki‐Miyaura Cross‐Coupling Reactions with Triflates or Nonaflates

“…Beier and coworkers reported the stereoselective SM cross coupling of enamido triflates with aryl boronic acids (Scheme 61). [79] While Pd(PPh 3 ) 4 provided the selective formation of enamide 210 with retention of the double bond, Pd(dppf)Cl 2 led to the formation of enamide 211 under inversion of the double bond.…”

“…Therefore, the yield dropped when comparing the 1 H‐NMR yield to the isolated yields (Scheme 61). Furthermore, despite considerable optimization the use of alkylboronic acids did not lead to any reaction, indicating the limitation of this transformation [79] …”

“…Furthermore, despite considerable optimization the use of alkylboronic acids did not lead to any reaction, indicating the limitation of this transformation. [79] Scheme 58. Difunctionalization of isoprene with Pd-catalyzed SM cross-coupling.…”

NH-1,2,3-triazoles as versatile building blocks in denitrogenative transformations

“…The products are useful building blocks, that can get involved in Pd-catalysed cross-coupling substitution reactions of the triflate group to access multifunctionalized enamide derivatives – attractive drug candidates and synthetic intermediates. 16 None of the methods mentioned was applicable with the less reactive alkyl-substituted acylating agents (Ac 2 O, AcCl), because the resulting acyltriazoles were resistant to ring cleavage even at elevated temperatures. 14…”