Nonprecious Metals Catalyzing Hydroamination and C–N Coupling Reactions

Abstract

This review highlights the recent achievements in replacing precious-metal-based catalysts with nonpreciousmetal-based catalysts in two important syntheses: hydroamination and C−N coupling reactions. The reported improvements are discussed in direct relation to the nature of the ligands, catalyst preparation methods, and the selection of other additives. Syntheses using ligand-free catalysts are also analyzed.

Electrophilic Aminating Agents in Total Synthesis

“…Hydroamination of alkenes and alkynes is ap owerful strategy for the formation of CÀNb onds.Such processes are complementary to aza-Heck reactions because the product is generated at alower unsaturation level. Avariety of strategies have emerged for effecting alkene and alkyne hydroaminations,i ncluding metal- [198][199][200][201][202][203][204][205][206][207][208][209][210][211] and Bronsted acid catalyzed [212][213][214] methods,r adical-mediated processes [215][216][217][218][219] and pericyclic-based methods. [220,221] Conventional hydroamination protocols are designed to enable the addition of an amine NÀHbond across an alkene or alkyne p-bond.…”

Hydroalkylation of Styrenes with Benzylamines by Potassium Hydride

“…Despite these advances, engagement of benzylamines in their deprotonative benzylic alkylation with styrenes remains elusive. When primary and secondary amines are employed, the base‐mediated deprotonation occurs on the amine site and the resulting amide anions show the propensity to undergo hydroamination [20–24] . Interestingly, Hultzsch observed that the reaction of benzylamine ( 4 ) and styrene ( 5 ) catalyzed by KN(SiMe 3 ) 2 and TMEDA affords not only hydroamination products 6 and 6′ , but also 1,3‐diphenylpropylamine ( 7 ) as a minor co‐product through hydroalkylation of styrene ( 5 ) ( Scheme 3).…”

Microwave-Assisted Synthesis and Characterization of [Rh2(OAc)4(L)2] Paddlewheel Complexes: A Joint Experimental and Computational Study

“…Based on the properties of the catalyst, this reaction can afford either the Markovnikov or anti-Markovnikov products ( Figure 2) [52][53][54][55][56][57][58]. Furthermore, a few Rh species have been reported as excellent catalysts for this process [59][60][61][62][63].…”