Reverse Cope elimination reactions. 1. Mechanism and scope
摘要:
N-4-Pentenyl- and N-5-hexenyl-N-methylhydroxylamine cyclized under mild conditions in a reverse Cope elimination reaction to give 1,2-dimethylpyrrolidine N-oxide and 1,2-dimethylpiperidine N-oxide, respectively. The reaction was shown to be concerted and thermodynamically controlled. The scope of this novel cyclization is discussed, and comparisons are made with the closely related and previously reported cyclization of monosubstituted alkenylhydroxylamines to give cyclic hydroxylamines.
A new cationic [N–O–S]zirconium complex (cat.) was developed to be an excellent catalyst for the intramolecular hydroamination of aminoalkenes with a large substrate scope from terminal alkenes to internal alkenes, and primary amines to secondary amines. The catalyst system can also tolerate various functional groups and perform sequential hydroamination of primary aminodienes.
Mild, Rhodium-Catalyzed Intramolecular Hydroamination of Unactivated Terminal and Internal Alkenes with Primary and Secondary Amines
作者:Zhijian Liu、John F. Hartwig
DOI:10.1021/ja710126x
日期:2008.2.6
We report a series of mild, rhodium-catalyzedhydroaminations of unactivated olefins with primary and secondary alkylamines to form the corresponding five- and six-membered products in excellent yields. The reactions form exclusively the product from hydroamination without competitive oxidative amination or olefin isomerization with catalysts generated from a biaryl dialkyl phosphine and an analogue
A method includes reacting an amino group, a composition including rhodium and an organic ligand, and a substrate having structural formula (I) in a reaction mixture.
R
1
is an organic group including a sp
3
carbon atom bonded to C
A
. R
2
is selected from the group consisting of hydrogen, methyl, and an organic group including a sp
3
carbon atom bonded to C
A
. R
3
and R
4
independently are selected from the group consisting of hydrogen, methyl, and an organic group including a sp
3
carbon atom bonded to C
B
. The method further includes forming a hydroaminated product in the reaction mixture.
Reverse Cope elimination reactions. 1. Mechanism and scope
作者:Engelbert Ciganek、John M. Read、Joseph C. Calabrese
DOI:10.1021/jo00123a013
日期:1995.9
N-4-Pentenyl- and N-5-hexenyl-N-methylhydroxylamine cyclized under mild conditions in a reverse Cope elimination reaction to give 1,2-dimethylpyrrolidine N-oxide and 1,2-dimethylpiperidine N-oxide, respectively. The reaction was shown to be concerted and thermodynamically controlled. The scope of this novel cyclization is discussed, and comparisons are made with the closely related and previously reported cyclization of monosubstituted alkenylhydroxylamines to give cyclic hydroxylamines.