Stoichiometric Reactions of CO₂ and Indium‐Silylamides and Catalytic Synthesis of Ureas

Abstract

The indium compounds In(N(SiMe ) ) Cl⋅THF (2) and In(N(SiMe ) )Cl ⋅(THF) (3) were shown to react with CO to give [(Me Si) N)InX(μ-OSiMe )] (X=N(SiMe ) 4, Cl 5). 0.05-2.0 mol % of the species 3 acts as a pre-catalyst for the conversion of aryl and alkyl silylamines under CO (2-3 atm) to give the corresponding ureas in 70-99 % yields. A proposed mechanism is supported by experimental and computational data.

Double Phosphinoboration of CO2: A Facile Route to Diphospha‐Ureas

“…The 31 P{ 1 H} NMR spectrum of 2 showedasingle resonancea td = À1.5 ppm with coupling to the carbon of CO 2 of J = 19 Hz in the 13 C-labelled product. The geometry of 2 is similar to that seen in 1 with the newly formed PÀCa nd OÀBd istances being 1.8590 (14) and 1.4099(18) ,respectively. The 11 B{ 1 H} NMR spectroscopic data showedasingle resonance at 53.1 ppm.…”

“…[4] In the intervening years, av ariety of B/N, [5] B/P, [6] Al/P, [7] and Si/P [5a, 8] systemsh ave been developed to capture or effect stoichiometric or catalytic reduction of CO 2 .A part from FLPs, basic main-group reagents have been exploited in reactionsw ith CO 2 .F or example, the carboxylations of N-heterocyclic carbenes [9] as well as silyl and germyl amides [10] have been reportedw hereas Dielmann and co-workers have described CO 2 captureb yh ighly basic phosphines incorporating imidazolin-2-ylidenamino substituents. [14] Interestingly, even thought he direct reactiono fC O 2 with amines [12c, 15] generally requires high pressure (14-140atm)a nd high temperature (130-170 8C), we have recently shown that judicious choiceo fs olventp romotes the reaction of CO 2 and silylamines to give silylcarbamates and ureas. [13] In 2018, we reportedi ndiumbased Lewis acid catalysts for the conversion of silylamines and CO 2 to ureas with liberation of silylethers.…”

Supported Porous Nanomaterials as Efficient Heterogeneous Catalysts for CO2 Fixation Reactions

“…Stephan et al. have reported the synthesis of substituted ureas by direct reaction of CO 2 (2–3 atm pressure) with aryl and alkylsilylamines over indium amides as catalyst . Here the In complex reacts with the aryl/alkylsilylamines to form an intermediate complex.…”

“…have reported the synthesis of substituted ureas by direct reactiono fC O 2 (2-3 atm pressure) with aryl and alkylsilylamines over indiumamides as catalyst. [205] Here the In complex reacts with the aryl/alkylsilylamines to form an intermediate complex. This is followed by the insertion of CO 2 molecules into the InÀNb ond and reaction with silyl carbamate species to form the substituted ureas.…”

Stoichiometric Reactions of CO2 and Indium‐Silylamides and Catalytic Synthesis of Ureas

“…POV-ray depictionso fa)2 and b) 3.C:black, N: blue, Cl: green, O: red, Si:light-pink, In:r ed-brown [26]. Scheme 2.…”