Search

2-tert-Butylimino -2-diethylamino-1,3 -dimethylperhydro-1,3,2 -diazaphosphorine supported on polystyrene (PS-BEMP) is an efficient catalyst for the addition of nitroalkanes (1-1.5 equiv.) to α,β-unsaturated carbonyl compounds (1.0 equiv.) in the absence of a reaction medium (solvent-free conditions). The corresponding γ-nitro carbonyl compounds have been isolated in excellent yields but the catalyst can be satisfactorily recovered and used for only 3 times due to the magnetic stirring which caused crunching of the catalyst beads thus hampering its complete recovery. To optimize the catalyst's reuse and improve the environmental efficacy of solvent-free conditions, the first solvent-free cyclic continuous-flow reactor has been set up. This reactor has allowed the product to be isolated in an almost quantitative yield by using a very small amount of organic solvent, making the recovery and reuse of the catalyst efficient and reproducible.

2-tert-Butylimino -2-diethylamino-1,3 -dimethylperhydro-1,3,2 -diazaphosphorine supported on polystyrene (PS-BEMP) is an efficient catalyst for the addition of nitroalkanes (1-1.5 equiv.) to α,β-unsaturated carbonyl compounds (1.0 equiv.) in the absence of a reaction medium (solvent-free conditions). The corresponding γ-nitro carbonyl compounds have been isolated in excellent yields but the catalyst can be satisfactorily recovered and used for only 3 times due to the magnetic stirring which caused crunching of the catalyst beads thus hampering its complete recovery. To optimize the catalyst's reuse and improve the environmental efficacy of solvent-free conditions, the first solvent-free cyclic continuous-flow reactor has been set up. This reactor has allowed the product to be isolated in an almost quantitative yield by using a very small amount of organic solvent, making the recovery and reuse of the catalyst efficient and reproducible.

Under solvent-free conditions, (E)-2-aryl-1-cyano-1-nitroethenes 1a–l rapidly react with 1-(trimethylsilyloxy)-cyclohex-1-ene (2a) with a complete regio- and diasteroselectivity and leading to the exclusive formation of the cis-fused hexahydro-4H-benzoxazine-2-oxides 3a–l, which were isolated without the need for a work-up procedure in excellent yields.

Amberlite IRA900N3 is an excellent organocatalyst for the azidation of α,β-unsaturated ketones with trimethylsilyl azide under solvent-free conditions. By avoiding the use of metallic species and of the organic reaction medium, the procedure is a green tool for the preparation of β-azido ketones under mild conditions with yields from good to excellent. The catalyst can be recovered and re-used with no loss of its efficiency.

Amberlite IRA900N3 is an excellent organocatalyst for the azidation of alpha,beta-unsaturated ketones with trimethylsilyl azide under solvent-free conditions. By avoiding the use of metallic species and of the organic reaction medium, the procedure is a green tool for the preparation of beta-azido ketones under mild conditions with yields from good to excellent. The catalyst can be recovered and re-used with no loss of its efficiency.

Under solvent-free conditions, (E)-2-aryl-1-cyano-1-nitroethenes 1a–l rapidly react with 1-(trimethylsilyloxy)-cyclohex-1-ene (2a) with a complete regio- and diasteroselectivity and leading to the exclusive formation of the cis-fused hexahydro-4H-benzoxazine-2-oxides 3a–l, which were isolated without the need for a work-up procedure in excellent yields.