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Topics in Current Chemistry (2018) 376:46
highly enantioenriched pyranonaphthoquinones 22a–g (Scheme 11) by a consecutive two-step process involving a squaramide-catalyzed Michael reaction and the
base-promoted oxa-Michael cyclization. The “wash and run” approach was also
employed in this case and the entire process (including two steps and in-line workup) was completed in 30 min. A washing time of 1 h was required between each run.
Starting from enantioenriched (2S,3S)-phenylglycidol, polystyrene-supported
benzotetramisole (BTM) catalyst 23 was prepared in a five-step sequence using a
copper-catalyzed click reaction (CuAAC) for bonding to the resin [47]. Supported
catalyst 23 (600 mg) was employed in a flow reactor (Scheme 12) set for performing
Scheme 9 Use of supported thiourea in continuous flow amination
Scheme 10 Use of supported squaramide in sequential continuous flow synthesis
39
Reprinted from the journal
Topics in Current Chemistry (2018) 376:46
highly enantioenriched pyranonaphthoquinones 22a–g (Scheme 11) by a consecutive two-step process involving a squaramide-catalyzed Michael reaction and the
base-promoted oxa-Michael cyclization. The “wash and run” approach was also
employed in this case and the entire process (including two steps and in-line workup) was completed in 30 min. A washing time of 1 h was required between each run.
Starting from enantioenriched (2S,3S)-phenylglycidol, polystyrene-supported
benzotetramisole (BTM) catalyst 23 was prepared in a five-step sequence using a
copper-catalyzed click reaction (CuAAC) for bonding to the resin [47]. Supported
catalyst 23 (600 mg) was employed in a flow reactor (Scheme 12) set for performing
Scheme 9 Use of supported thiourea in continuous flow amination
Scheme 10 Use of supported squaramide in sequential continuous flow synthesis
39
Reprinted from the journal