Gold-Catalyzed 1,2-Difunctionalizations of Aminoalkynes Using Only N- and O-Containing Oxidants
摘要:
We report two viable routes for the 1,2difunctionalization of aminoalkynes using only oxidants. In the presence of a gold catalyst, nitrones enable the oxoamination of aminoalkynes 1 to form 2-aminoamides 2. With a suitable gold catalyst, nitrosobenzenes implement an alkyne/nitroso metathesis of the same substrates to give 2-oxoiminylamides 3. These two novel oxidations also provide 1,2-aminoalcohols with opposite regioselectivity via NaBH4 reduction in situ.
A transition metal-free facile access to β-amino alcohols via epoxide ring-opening with amine nucleophiles. The process is carried out at room temperature with only 0.5 mol % catalyst loading. A wide spectrum of styrene oxide and aniline derivatives are readily tolerated by this procedure. A highly effective gram-scale synthesis with a high TON=842 is also reported.
A general biocatalytic process of intermolecular aminohydroxylation of styrenes with aniline has been achieved for efficient one-pot preparation of enantiopure β-amino alcohols. The reaction involves first asymmetric epoxidation of alkene substrates by a heme-dependent monooxygenase (P450) or the FAD-dependent styrene monooxygenase, followed by the aminolysis of nascent epoxide intermediates with aniline
Thiourea catalyzed aminolysis of epoxides under solvent free conditions. Electronic control of regioselective ring opening
作者:Swapandeep Singh Chimni、Neeraj Bala、Vaibhav A. Dixit、Prasad V. Bharatam
DOI:10.1016/j.tet.2010.02.053
日期:2010.4
A reactant economizing process for the regioselective aminolysis of epoxides using equimolar quantities of reactants catalyzed by the double hydrogen bond donor N,N'-bis[3,5-bis(trifluoromethyl)phenyl]thiourea is reported. Regioselectivity of the reaction is controlled by the electronic nature of the substituent on the styrene oxide, which has been substantiated on the basis of C-13 NMR data and DFT calculations. (C) 2010 Elsevier Ltd. All rights reserved.
Gold-Catalyzed 1,2-Difunctionalizations of Aminoalkynes Using Only N- and O-Containing Oxidants
作者:Anupam Mukherjee、Ramesh B. Dateer、Rupsha Chaudhuri、Sabyasachi Bhunia、Somnath Narayan Karad、Rai-Shung Liu
DOI:10.1021/ja208150d
日期:2011.10.5
We report two viable routes for the 1,2difunctionalization of aminoalkynes using only oxidants. In the presence of a gold catalyst, nitrones enable the oxoamination of aminoalkynes 1 to form 2-aminoamides 2. With a suitable gold catalyst, nitrosobenzenes implement an alkyne/nitroso metathesis of the same substrates to give 2-oxoiminylamides 3. These two novel oxidations also provide 1,2-aminoalcohols with opposite regioselectivity via NaBH4 reduction in situ.