Pd/C-Catalyzed Synthesis of Oxamates by Oxidative Cross Double Carbonylation of Amines and Alcohols under Co-catalyst, Base, Dehydrating Agent, and Ligand-Free Conditions

Abstract

This work reports a mild, efficient, and ligand-free Pd/C-catalyzed protocol for the oxidative cross double carbonylation of amines and alcohols. Notably, the reaction does not requires any base, co-catalyst, dehydrating agent, or ligand. Pd/C solves the problem of catalyst recovery, and the catalyst was recycled up to six times.

Crystal structure of 2-(bis(4-methoxyphenyl)amino)-2-oxoacetic acid, C16H15NO5

“…In addition, aryl oxamic acids can be used as intermediates for the synthesis of various classes of compounds including heterocycles [9][10][11][12]. Oxamates can be synthesized by the use of various synthetic procedures [13][14][15][16][17].…”

An Improved Strategy for the Synthesis of Ethylene Glycol by Oxamate‐Mediated Catalytic Hydrogenation

“…Direct synthesis of EG starting from syngas under reductive conditions, although ap romising method, has significant difficulties in overcoming low reactivity and selectivity.A lternative methods, such as EG preparation from methanol, formaldehyde, and methylf ormate, also have some merit, but low selectivity limits their application too. [14] To extend our continued interest in these carbonylation and hydrogenation reactions, we used oxamates as key intermediates for an improved EG synthesis.Herein, we report at wo-step approachf or the synthesis of EG by oxidative crossd ouble carbonylation of piperidine and ethanol and subsequent catalytic hydrogenation of oxamates by using Milstein's catalyst(Scheme 2).The oxamates were synthesized according to our previously reported method (Scheme 3). Rapid industrialization in recent years, which has greatly increased the amounts of CO andC O 2 emitted into the atmosphere, is am ajor global concern.…”

“…[5][6][7][8] Given the commercial importance of EG, academic and industrial attention has increasedinr ecent years to find alternative methodsfor its preparation. [14] Initial attempts focusedo ne xploring the feasibility of the proposed process.We first tested various Ru catalyst precursors and ligandsi n the hydrogenation of oxamate;R u(OAc) 2 ,R uCl 2 ,a nd [Ru(acac) 3 ] were found to be ineffective catalysts with variousl igands (Table 1, entries 1-3). The use of easily available feedstocks in new transformations is as ource of innovation in materials science and chemistry.…”

“…Rapid industrialization in recent years, which has greatly increased the amounts of CO andC O 2 emitted into the atmosphere, is am ajor global concern. [14] To extend our continued interest in these carbonylation and hydrogenation reactions, we used oxamates as key intermediates for an improved EG synthesis. Upgrading C1 feedstocks (for example, CO, CO/H 2 ,o rC O 2 )t hrough CÀCb ond formationi sa ne conomical and sustainable means of synthesizing bulk chemicals.…”

Pd/C‐Catalyzed Cyclizative Cross‐Coupling of Two ortho‐Alkynylanilines under Aerobic Conditions: Synthesis of 2,3′‐Bisindoles

“…We note that there are only a few examples of using Pd/C as a pre-catalyst for Pd II -catalyzed oxidative transformations. [16] With the optimum conditions in hand, the scope of the reaction was next examined (Table 2). These conditions were applicable not only to N-acetyl-o-ethynylanilines, but also to N-benzoyl-(5 n) and N-Boc-o-ethynylanilines with N-Boc-o-ethynylanilines being in general the best substrates.…”