Feedstock Reagents in Metal‐Catalyzed Carbonyl Reductive Coupling: Minimizing Preactivation for Efficiency in Target‐Oriented Synthesis

Abstract

Use of abundant feedstock pronucleophiles in catalytic carbonyl reductive coupling enhances efficiency in target‐oriented synthesis. For such reactions, equally inexpensive reductants are desired or, ideally, corresponding hydrogen autotransfer processes may be enacted wherein alcohols serve dually as reductant and carbonyl proelectrophile. As described in this Minireview, these concepts allow reactions that traditionally require preformed organometallic reagents to be conducted catalytically in a byproduct‐free manner from inexpensive π‐unsaturated precursors.

Rhodium‐katalysierte dealkenylierende Arylierung von Alkenen mit Arylboronverbindungen

“…Basierend auf den oben genannten Beobachtungen und der einschlägigen Literatur [10, 14, 15] wird ein plausibler mechanistischer Weg vorgeschlagen, wie in Schema 3 dargestellt. Erstens bildet die Reaktion von [RhCp*(MeCN) 3 ][SbF 6 ] 2 mit EtOH eine aktive Katalysatorspezies [Cp*Rh III X]‐H (X=SbF 6 oder OEt) zusammen mit CH 3 CHO (CH 3 CHO wurde durch GCMS nach der Reaktion von 1 e und 2 a nachgewiesen, siehe Hintergrundinformationen) [14] .…”

Intermolecular diastereoselective annulation of azaarenes into fused N-heterocycles by Ru(II) reductive catalysis

“…For instance, in addition to the well-known reductive amination applied for amine syntheses 15 , 16 , several groups such as Beller 17 , 18 , Kempe 19 , 20 , Kirchner 21 , 22 , Liu 23 – 25 , and others 26 – 29 have applied borrowing-hydrogen strategy to alkylate amines and the α -site of carbonyl compounds with alcohols. Krische has demonstrated elegant contributions on the linkage of alcohols/carbonyls with unsaturated C–C bonds 30 – 32 . Bruneau et al have achieved β -C(sp 3 )−H alkylation of N-alkyl cyclic amines 33 , 34 .…”

Nickel-Catalyzed Intramolecular Hydroalkenylation of Imines

“…Due to the increasing demand for efficient and atom-economical organic synthesis processes, direct coupling of carbonyls with simple alkenes has attracted extensive attention and has made remarkable progress . As part of our ongoing study of C–C coupling reactions with 100% atom economy, we became interested in Ni-catalyzed imine–alkene coupling reactions.…”