Rhodium‐Catalyzed Bis‐Hydroaminomethylation of Linear Aliphatic Alkenes with Piperazine

Abstract

An efficientp rotocolw as developed to prepare as erieso fd ialkylpiperazines via Rh-catalyzed bis-hydroaminomethylation of linear aliphatic alkenes with piperazine.T he well-known Rh/Biphephos catalytic system was applied, yielding the desired dialkylpiperazines within six tandemc atalytic steps,a lready at low catalyst loadings of 0.1mol%. Fort he model alkene 1-octene,g ood yields and linearities of 80% and 77:23, respectively,w ere achieved under optimized conditions.I nfluences on the catalytic system regarding n/iso ratio, possible side reactions and the reactionp ath are discussed on the basis of yield vs. time plots and parameter optimization. With the developedg eneral protocol, other linear, functionalized and branched substrates were effectively transformed to the corresponding linear N,Ndisubstituted piperazines.

From Oleo Chemicals to Polymer: Bis‐hydroaminomethylation as a Tool for the Preparation of a Synthetic Polymer from Renewables

“…Recently, we developed a bis ‐hydroaminomethylation ( bis ‐HAM) protocol with linear alkenes and piperazine to furnish N , N ‐dialkyl‐substituted piperazines having a principal carbon efficiency of 100 % and for which water was the only coproduct . The renewables methyl 10‐undecenoate ( 1 ) and 10‐undecen‐1‐ol ( 2 ) were successfully transformed within this rhodium‐catalyzed auto‐tandem reaction into linear bifunctional molecules in a resource‐efficient fashion (Scheme ).…”

“…The remaining 28 % of the diester compounds comprised at least one branched alkyl chain, although also branched/branched substituted diesters with different branching were identified . These results are in good agreement with those previously reported . Also, in the synthesis of linear diol 4 from unsaturated alcohol 2 , quantitative conversion was obtained and a selectivity of 70 % to the linear product was observed.…”

“…[14] These results are in good agreement with those previously reported. [12] Also, in the synthesis of linear diol 4 from unsaturated alcohol 2,q uantitative conversion waso btained and as electivity of 70 %t ot he linear product was observed.…”

“…Recently,w edeveloped a bis-hydroaminomethylation (bis-HAM) protocol with linear alkenes and piperazine to furnish N,N-dialkyl-substitutedp iperazines having ap rincipal carbon efficiency of 100 %a nd for which water was the only coproduct. [12] The renewables methyl 10-undecenoate (1)a nd 10-undecen-1-ol (2)w ere successfully transformed within this rhodium-catalyzed auto-tandem [13] reaction into linear bifunctional molecules in ar esource-efficientf ashion (Scheme 2). Bis-HAM consists of initial Rh-catalyzed hydroformylation to form the intermediate linear aldehyde, which in situ undergoes rhodiumcatalyzed reductivea mination at both nitrogen atoms of the diamine piperazine.…”

Synthesis of Industrial Primary Diamines via Intermediate Diols – Combining Hydroformylation, Hydrogenation and Amination

“…The compatibility of the different reaction parameters required for each individual reaction step poses a significant challenge when it comes to developing new tandem catalysis reactions. Tandem reactions such as hydroaminomethylation, hydrohydroxymethylation,, aldol condensation or epoxidation all include a hydroformylation step to obtain the intermediate aldehyde, which then undergoes further conversions to achieve the desired product. Recent investigations using a rhodium and ruthenium catalyst have combined dcpd hydroaminomethylation with the dealkylation of the resulting secondary amines with ammonia to obtain TCD‐diamine.…”