A Study of Aerobic Photooxidation with a Continuous-Flow Microreactor

Abstract

We report the development of an aerobic photooxidation process with a continuous-flow microreactor that can form a slug flow region on the chip. The approach solved several problems raised by ­using batch systems.

Key words

oxygen - photooxidation - green chemistry - microreactor - slug flow

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• 11 Typical Procedure with Flow Microreactor: A solution of the substrate (0.3 mmol) and photosensitizer (0.1 equiv) in EtOAc (0.6 mL) was introduced into one of the channels by using a syringe pump. Simultaneously, molecular oxygen (0.1 MPa) was introduced into the second channel from a gas cylinder controlled by a mass flowmeter. Both streams were mixed in the channel of the reactor chip to form a slug flow. Light (375 nm) from an LED array (sum: 11.4 W) was used to irradiate the slug flow from a distance of 1 mm from the chip surface The product was collected in a vial tube and analyzed by ¹H NMR spectroscopy.