Chiral Polyamino Alcohols via Hydroaminomethylation: A New Class of Polyamines for Dendritic Cores and Ligand Precursors

Abstract

In this contribution, the synthesis of a new class of chiral polyamino alcohols (PAA) via a twostep hydroaminomethylation/hydrolysis procedure is reported. The chiral polyamines are obtained by hydroaminomethylation of N-olefinic oxazolidinones with different amines in first step followed by hydrolysis of the resulting polyamines to give the chiral PAA in the second step. The dendritic chiral PAA (Mw = 1300-1400 g mol À1) are also synthesized efficiently through a multifold hydroaminomethylation/ hydrolysis procedure. Furthermore, chiral PAA are investigated as ligands in ruthenium-catalyzed asymmetric hydrogen transfer reduction of acetophenone to 1-phenyl alcohol.

Hydroaminomethylation of the Renewable Limonene with Ammonia in an Aqueous Biphasic Solvent System

“…For this transition metal-catalyzed tandem reaction a catalyst based on [Rh(cod)Cl] 2 was employed which showed high activities in reported hydroaminomethylation reactions [33][34][35][36][37][38][39][40]. In Figure 3.…”

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

“…However, ar eaction path via mono-HAM intermediate 4a is also plausible (Path B, Scheme3). Thec atalytic species was derived in situ from the ap- [30] linear ali- In initial investigations,w en oticed as trong influence of the syngas ratio upon the outcome of the experiment. Therefore,t he syngas ratio was first optimized systematically in ar ange of H 2 /CO from 1t o4 ( Table 2).…”

“…Thus,n ol igands were needed.I no nly as ingle example,aterminal alkene with no substituent at the a-position was applied but with major modification. [30] Thei nitial hydroformylation of an Nallyloxazolidin-2-one derivative was conducted in the absence of piperazine,u nder the influence of Biphe- phos as ligand, to achieve reasonable selectivities for the linear aldehyde of 87% after 48 hw ith 1mol% [Rh(cod)Cl] 2 .I nasecond step,p iperazinea nd additional [Rh] were added and the reductive amination of the linear aldehyde then furnished the desired bis-HAM product in aone-pot manner.…”

“…[25,26] But only in the last two decades,i t became ag eneral tool for the production of various amines (fine chemicals,p harmaceuticals,e tc.) from olefins,p articularly due to the work of Eilbracht, [27][28][29][30][31][32][33] Beller, [23,[34][35][36] and Zhang. [37][38][39][40][41][42] Generally, hydroaminomethylations are,h owever, limited to the aforementioned three auto-tandem catalytic steps and only scattered examples deal with the extensiono ft his sequence.A mong them are combinations of HAM with concurrent esterification of the applied amino acid, [43] formation of the required syngas atmosphere from CO 2 by preliminary reversed water-gas shift (RWGS) reaction [31] andt he access to linear aminesf rom internal alkenes by isomerizing hydroaminomethylation.…”

“…[30,49,50] Moreover, 1,4-bis-alkylated piperazines are accessiblei nbis-HAM yields,w hich have been otherwise synthesized by employing mono-alkylated piperazines under hydroaminomethylation conditions. [34,44,[49][50][51] Additionally,s ymmetrical bis-alkylated piperazines exhibit biological activity and hence,t heir straightforward synthesis is of considerable interest.…”