- Ligand-Enabled Catalytic C-H Arylation of Aliphatic Amines by a Four-Membered-Ring Cyclopalladation Pathway
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A palladium-catalyzed C-H arylation of aliphatic amines with arylboronic esters is described, proceeding through a four-membered-ring cyclopalladation pathway. Crucial to the successful outcome of this reaction is the action of an amino-acid-derived ligand. A range of hindered secondary amines and arylboronic esters are compatible with this process and the products of the arylation can be advanced to complex polycyclic molecules by sequential C-H activation reactions. Four corners: A palladium-catalyzed C-H arylation of aliphatic amines with arylboronic esters is described to proceed by a four-membered-ring cyclopalladation pathway. Crucial to the successful outcome of this reaction is the action of an amino-acid-derived ligand. A range of hindered secondary amines and arylboronic esters are compatible with this process and the products of the arylation can be advanced to complex polycyclic molecules by sequential C-H activation reactions.
- He, Chuan,Gaunt, Matthew J.
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supporting information
p. 15840 - 15844
(2016/01/29)
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- Highly active metal-free catalysts for hydrogenation of unsaturated nitrogen-containing compounds
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New highly active ansa-ammonium borate catalysts for the direct metal-free hydrogenation of imines were prepared by tuning of the basicity and steric bulkiness of their amine moieties. The highest catalytic activity among previously reported organocatalytic systems was shown for a wide range of nitrogen-containing substrates. The first example of asymmetric imine hydrogenation based on the ansa-ammonium borate concept was demonstrated. Furthermore, effective catalyst recovery by extraction of the acidic solution with an organic solvent followed by dehydration with TMSBr was elaborated. The initial findings highlight the development of more effective chiral ansa-ammonium borates for enantioselective hydrogenation. Therefore, the progress achieved in the ansa-ammonium borate concept makes it very promising for further elaboration with the aim to obtain industrially applicable catalysts. Copyright
- Sumerin, Victor,Chernichenko, Konstantin,Nieger, Martin,Leskelae, Markku,Rieger, Bernhard,Repo, Timo
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scheme or table
p. 2093 - 2110
(2011/11/06)
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- Polysubstituted 2-morpholones, related compounds, processes for their preparation, and U-V light stabilized compositions
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An essentially single stage reaction has been discovered in which a disubstituted ethanolamine, that is, a 2,2'-substituted-2-aminoethanol, may be reacted with a haloform and a carbonyl containing compound selected from the group consisting of monoketones and benzaldehyde, in the presence of an alkali metal hydroxide, and optionally in the presence of a phase transfer catalyst, to produce an alkali metal hydroxyethylaminoacetate ("HEAA") which has N-adjacent C atoms on which there are a total of at least three substituents (hence "polysubstituted"), and one or both pairs of substituents on each N-adjacent C atom may be cyclized. The HEAA may be cyclized by the action of a mineral acid to produce a 2-morpholone hydrochloride which is characterized by having a total of at least three substituents on the N-adjacent C atoms of the ring. The 2-morpholone so produced may be reduced to a polysubstituted aminodiol. The aminodiol so produced may be cyclized with an alkane sulfonic acid to yield a polysubstituted morpholine which could not otherwise have been made. The aminodiol may also be alkylated to produce diethers with polysubstituted N-adjacent C atoms. If the aminodiol is tosylated, a polysubstituted crown ether is produced with plural polyalkylene groups. The foregoing HEAA and related compounds are used as u-v light stabilizers in novel compositions in which a small but effective amount of one or more of the HEAA and related compounds is incorporated, in an amount sufficient to produce desirable stabilization against degradation by u-v light in a wide variety of organic materials.
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- Polysubstituted 2-morpholones
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An essentially single stage reaction has been discovered in which a disubstituted ethanolamine, that is, a 2,2'-substituted-2-aminoethanol, may be reacted with a haloform and a carbonyl containing compound selected from the group consisting of monoketones and benzaldehyde, in the presence of an alkali metal hydroxide, and optionally in the presence of a phase transfer catalyst, to produce an alkali metal hydroxyethylaminoacetate ("HEAA") which has N-adjacent C atoms on which there are a total of at least three substituents (hence "polysubstituted"), and one or both pairs of substituents on each N-adjacent C atom may be cyclized. The HEAA may be cyclized by the action of a mineral acid to produce a 2-morpholone hydrochloride which is characterized by having a total of at least three substituents on the N-adjacent C atoms of the ring. The 2-morpholone so produced may be reduced to a polysubstituted aminodiol. The aminodiol so produced may be cyclized with an alkane sulfonic acid to yield a polysubstituted morpholine which could not otherwise have been made. The aminodiol may also be alkylated to produce diethers with polysubstituted N-adjacent C atoms. If the aminodiol is tosylated, a polysubstituted crown ether is produced with plural polyalkylene groups. The foregoing HEAA and related compounds are used as u-v light stabilizers in novel compositions in which a small but effective amount of one or more of the HEAA and related compounds is incorporated, in an amount sufficient to produce desirable stabilization against degradation by u-v light in a wide variety of organic materials.
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