Selective Amine Cross‐Coupling Using Iridium‐Catalyzed “Borrowing Hydrogen” Methodology

Abstract

Something borrowed: Amine cross‐coupling reactions are catalyzed using [{Cp*IrI2}2] (Cp*=C5Me5) in the absence of a base. A range of anilines were converted into their N‐isopropyl derivatives, and the same process was also effective for alkylation of benzylamines and other aliphatic primary amines.

Alkylation of Amines with Alcohols and Amines by a Single Catalyst under Mild Conditions

“…Since then, great progress has been made in this area, allowing the reaction to be carried out under milder conditions,7j, 10 with broader substrate scope,7h or even in an enantioselective manner 7m. 11 Notable contributions have come from the groups of Beller,3, 7p,q,s, 12 Williams,7a,c,d,f,h,r,t–v,x, 13 Fujita,14 Kempe,7z, 10, 15 Martín‐Matute,16 Crabtree,17 Yus,7b, 18 Peris,7g Andersson,7j Milstein,19 Zhao7m, 11b and others 20. The strategy could be further extended to the cross coupling of amines as reported by the groups of Beller,7p,q Peris7g and Williams 7r.…”

“…The versatility of the system was further examined for the cross‐coupling of amines (Table 4), which is normally carried out at temperatures higher than 150 °C 7g,p–r. 21 Delightfully, the reaction of aniline with diisopropylamine proceeded smoothly under the same mild reaction conditions as those for the alkylation with alcohols.…”

Reduktive Aminierung ohne externe Wasserstoffquelle

“…Diese Methode ist atomökonomischer, benötigt weniger Aufreinigungsschritte und generiert weniger Lösungsmittelabfälle. Alternativ sind kürzlich Aminierungen von Alkoholen statt Carbonylverbindungen entwickelt worden, die über einen internen Redoxprozess ablaufen 14–17…”

External‐Ligand‐Free Aerobic Oxidation of N‐ and C‐Containing Cyclic Systems under Pd‐Catalyzed Conditions

“…The formationo f4b is believed to undergo ar eactiono fa niline and cyclohexanonet hrough bor-rowingh ydrogen processes. [11] The oxidationo fb enzocyclohexanyl amine was also straightforward, the naphthalene amine 4c being obtainedi namoderate yield of 36 %. Interestingly,o nce ad icyclohexanyl-substituted amine was employed, Table 1.…”