Tertiary amino alcohols have been shown to be effective co-solvents for CO 2 capture when used in conjunction with aminosilicones. In some cases, they demonstrated a marked increase in CO 2 capture compared to an equivalent weight loading of triethylene glycol and also showed a lower viscosity at a given CO 2 loading. These materials may be useful as cosolvents in carbon capture processes using aminosilicones.

An alternative to nucleophilic chemistry for the construction of α‐substituted amides and amine derivatives from imines is provided by the Stille‐type coupling of imines with organotin reagents and acid chlorides (see scheme). This Pd‐catalyzed reaction is suitable for components with a range of functional groups and has been extended into a four‐component‐coupling reaction with carbon monoxide. dba=dibenzylideneacetone, RT=room temperature.

Two new routes have been developed to generate manganese-chelated amides from imine and carbon monoxide building blocks. The reaction of (CO) 5 MnR (R ) CH 3 , Ph) with (ptolyl)(R 1 )dNR 2 (R 1 ) H, t Bu; R 2 ) alkyl, H) results in the generation of the cyclometalated imine complexes (CO) 4 Mn[η 2 -4-CH 3 -2-(C(R 1 )dNR 2 )-C 6 H 3 ] in 50-84% isolated yield. However, when the reaction of (p-tolyl)(H)CdNCH 3 with (CO) 5 MnCH 3 is performed in the presence of AlCl 3 , the product of sequential carbon monoxide and imine insertion is generated in 35% yield: (CO) 4 Mn[η 2 -C(H)(p-tolyl)N(CH 3 )COCH 3 ]. The addition of PPh 3 to the latter complex results in replacement of a carbonyl ligand and formation of the isolable fac-(CO) 3 (PPh 3 )-Mn[η 2 -C(H)(p-tolyl)N(CH 3 )COCH 3 ]. In an alternative route to metal-bound amides, the oxidative addition of the N-acyl iminium salt (p-tolyl(H)CdN(CH 3 )COPh + Clto (CO) 5 Mn -Na + has been found to lead to the generation of the product of subsequent CO insertion, (CO) 4 Mn-[η 2 -COC(H)(p-tolyl)N(CH 3 )COPh]. The latter represents the first example of a acyl-bound transition-metal-chelated R-amino acid complex and has been characterized by X-ray crystallography. Preliminary reactivity studies demonstrate that (CO) 4 Mn[η 2 -COC(H)(ptolyl)N(CH 3 )COPh] reacts with PPh 3 to generate the unchelated cis-(CO) 4 (PPh 3 )Mn[COC-(H)(p-tolyl)N(CH 3 )COPh], while reaction with NaBH 4 leads to the liberation of the amide (p-tolyl)CH 2 N(CH 3 )COPh, rather than the amino acid residue.

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Multicomponent reactions Multicomponent reactions O 0359Imines in Stille-Type Cross-Coupling Reactions: A Multicomponent Synthesis of α-Substituted Amides. -A convenient and general one-pot synthesis of α-substituted amides and N-protected amines by a palladium-catalyzed three-component coupling of imines, acid chlorides or chloroformates, and organotin compounds is described. This process represents an oxidative addition/reductive elimination-based alternative to nucleophilic approaches to C-C bond formation with imines, in which imines are activated towards addition to palladium by RCOCl. -(DAVIS, J. L.; DHAWAN, R.; ARNDTSEN*, B. A.; Angew. Chem., Int. Ed. 43 (2004) 5, 590-594; Dep. Chem., McGill Univ., Montreal, Que. H3A 2K6, Can.; Eng.) -Klein 19-048