73124-11-5Relevant academic research and scientific papers
A general nickel-catalyzed hydroamination of 1,3-dienes by alkylamines: Catalyst selection, scope, and mechanism
Pawlas, Jan,Nakao, Yoshiaki,Kawatsura, Motoi,Hartwig, John F.
, p. 3669 - 3679 (2007/10/03)
A simple colorimetric assay of various transition-metal catalysts showed that the combination of DPPF, Ni(COD)2, and acid is a highly active catalyst system for the hydroamination of dienes by alkylamines to form allylic amines. The scope of the reaction is broad; various primary and secondary alkylamines react with 1,3-dienes in the presence of these catalysts. Detailed mechanistic studies revealed the individual steps involved in the catalytic process. These studies uncovered unexpected thermodynamics for the addition of amines to π-allyl nickel complexes: instead of the thermodynamics favoring the reaction of a nickel allyl with an amine to form an allylic amine, the thermodynamics favored reaction of a nickel(0) complex with allylic amine in the presence of acid to form a Ni(II) allyl. The realization of these thermodynamics led us to the discovery that nickel and some palladium complexes in the presence or absence of acid catalyze the exchange of the amino groups of allylic amines with free amines. This exchange process was used to reveal the relative thermodynamic stabilities of various allylic amines. In addition, this exchange reaction leads to racemization of allylic amines. Therefore, the relative rate for C-N bond formation and cleavage influences the enantioselectivity of diene hydroaminations.
Synthetic and kinetic aspects of nickel-catalysed amination of allylic alcohol derivatives
Bricout, Herve,Carpentier, Jean-Francois,Mortreux, Andre
, p. 1073 - 1084 (2007/10/03)
The design of efficient nickel-based catalytic systems for coupling of diethylamine (1) with esters and ether derivatives of allyl alcohol (2a-c) and related allyl-substituted compounds (4a-e) is reported. Special attention is paid to solvent and salt effects on catalytic activities and kinetic profiles for the formation of allyllamines. The results are discussed in terms of the influence of some reaction parameters (polarity, ion exchange processes, substrate) on the rate determining step of the catalytic cycle.
SYNTHESE DE β-FLUOROAMINES
Toulgui, Ch.,Chaabouni, M. M.,Baklouti, A.
, p. 385 - 391 (2007/10/02)
β-Fluoroamine compounds were obtained from 2-fluorotosylates by action of an excess of amines in dimethyl sulfoxide.The substitution of the tosyl group by amine takes place in all the studied cases whereas the elimination of toluene-p-sulphonic acid (HOTs) is not observed.This process is a good general method for the synthesis of primary, secondary and tertiary β-fluoroamines in acceptable yields.
HIGHLY ENANTIOSELECTIVE ISOMERIZATION OF PROCHIRAL ALLYLAMINES CATALYZED BY CHIRAL DIPHOSPHINE RHODIUM(I) COMPLEXES. PREPARATION OF OPTICALLY ACTIVE ENAMINES
Tani, Kazuhide,Yamagata, Tsuneaki,Akutagawa, Susumu,Kumobayashi, Hidenori,Taketomi, Takanao,et al.
, p. 5208 - 5217 (2007/10/02)
Rh(I) complexes of types ClO4 and n>ClO4 (diphosphine = cis-chelating tertiary diphosphine; diene = 1,5-cyclooctadiene or norbornadiene; S = solvent) were found to be effective catalists for allylic hydrogen migration of tertiary and secondary allylamines to give the corresponding (E)-enamines and imines, respectively.Studies on diphosphine ligands with respect to the catalytic activity and product selectivity led to the discovery of a fully aryl-substituted diphosphine, BINAP , which produces very active Rh(I) complex catalysts.With ClO4 (COD = 1,5-cyclooctadiene) or n>ClO4 as catalyst, (Z)-(diethylnerylamine, 1) or (E)-N,N-diethyl-3,7-dimethyl-2,6-octadienylamine (diethylgeranylamine, 2) was isomerized into the racemic (E)-enamine (E)-N,N-diethyl-3,7dimethyl-1,6-octadienylamine (citronellenamine, 3) with a chemical selectivity of over 95percent, the 6-double bond being retained intact.A variety of substituted allylamines serves as the substrate, e.g., (E)-N,N-dimethyl-2-butenylamine, N,N-dimethyl-2-methyl-2-propenylamine, N,N-dimethyl-3-methyl-2-butenylamine, N,N-dimethyl-3-phenyl-2-butenylamine.Asymmetric isomerization of prochiral allylamines producing optically active enamines or imines can be effected with cationic Rh(I) complexes of various chiral diphosphine ligands such as (2R,3R)-DIOP and others.The ligand that gives the highest optical yield was (+)- or (-)-BINAP.Virtually perfect enantioselectivity (95-99percent ee) was achieved with + for the isomerization of 1 or 2 into the optically active (E)-enamine (3).A clear stereochemical correlation was established between the olefin geometry (E or Z) of substrates, the configuration of the chiral diphosphines (R or S), and the chiral carbon configuration of the product enamines (R or S).The present catalytic system thus provides a convenient and practical access to optically active aldehydes.For example, optically pure natural citronellal can be produced either from nerylamine with the Rh(I)-(+)-BINAP catalyst or from geranylamine with the Rh(I)-(-)-BINAP complex catalyst.
