A palladium-catalyzed intramolecular amination of alkenes with retention of olefin functionalization was achieved under mild reaction conditions. In the presence of palladium catalyst, the tosyl-protected amine can directly couple with a double bond to provide versatile dihydropyrrole derivatives in moderate to excellent yields.
Solvent-free synthesis of N-sulfonylimines using microwave irradiation
作者:András Vass、József Dudás、Rajender S. Varma
DOI:10.1016/s0040-4039(99)00867-9
日期:1999.7
N-Sulfonylimines are prepared expeditiously in a one-pot solventless operation by microwave thermolysis of aldehydes and sulfonamides in the presence of benign reagents, calcium carbonate and montmorillonite K 10 clay.
The Mannich reaction of methylsilyl enol ether with arylaldimine proceeded in the presence of a catalytic amount of lithium chloride in dimethylformamide at room temperature. The reaction was mild enough to apply to aldimines having the AcO, TBDMSO, or MeS group. Microwave irradiation accelerated the reaction substantially to reduce reaction time.
Preparation of<i>N</i>-Arylsulfonyl Imines from Sulfonamides and Aryl Aldehydes Using Magnesium Oxide as a Heterogeneous and Reusable Catalyst Under Solvent-Free Conditions
An efficient solvent-free procedure for the preparation of N-arylsulfonyl imines from sulfonamides and aryl aldehydes in the presence of a catalytic amount of magnesium oxide and tetrabutylammonium bromide (TBAB) under microwave irradiation is described. The advantages of this method are good to high yields, short reaction times, low cost, and matching with green chemistry protocols.
Enantioselective Catalytic Ring Expansion of Methylenecyclopropane Carboxamides Promoted by a Chiral Magnesium Lewis Acid
作者:Catherine Taillier、Mark Lautens
DOI:10.1021/ol0628614
日期:2007.2.1
A catalytic enantioselective ring expansion of monoactivated methylenecyclopropanes (MCP) in the presence of N-tosyl aldimines was developed using a chiral bis(oxazoline) ligand-MgI2 complex. After evaluation of ligands and optimization of the reaction conditions, the reaction has been applied to a variety of aromatic and heteroaromatic aldimines providing the corresponding trans-C2,C3-disubstituted