ABSTRACT
Introduction ............................................................................................................ 111 Reaction Procedures ............................................................................................... 112
Representative Procedure for the Nucleophilic Addition of Nitroalkanes 2a,b to α,β-Unsaturated Ketones 1a-c Catalyzed by PS-BEMP in a Cyclic Flow Reactor ..................................................................................................... 112
Notes ...................................................................................................................... 113 Discussion .............................................................................................................. 114 Importance in Green Chemistry Context ............................................................... 116 Highlights of the Present Contribution .................................................................. 116 Acknowledgments .................................................................................................. 119 References .............................................................................................................. 119
can be very efcient to reduce the E-factor,8 and in general the environmental cost of synthetic processes. Highlights of our results are the recovery of the products with a minimal amount of organic solvent, as well as the reproducible recovery of the solid catalyst and its repetitive use in consecutive processes. We have studied the reactivity of nitro compounds in unconventional media, and as a continuation of our interest in this context,9,10 we have dened an efcient protocol for the Michael addition of nitroalkanes (2a,b) to α,β-unsaturated ketones (α,β-enones, 1a-c), catalyzed by 2-tertbutylimino-2-diethylamino-1,3-dimethylperhydro-1,3,2-diazaphosphorine supported on polystyrene (PS-BEMP)7c in ow (Scheme 8.1).
