Batch versus Flow Photochemistry: A Revealing Comparison of Yield and Productivity
作者:Luke D. Elliott、Jonathan P. Knowles、Paul J. Koovits、Katie G. Maskill、Michael J. Ralph、Guillaume Lejeune、Lee J. Edwards、Richard I. Robinson、Ian R. Clemens、Brian Cox、David D. Pascoe、Guido Koch、Martin Eberle、Malcolm B. Berry、Kevin I. Booker-Milburn
DOI:10.1002/chem.201404347
日期:2014.11.10
The use of flowphotochemistry and its apparent superiority over batch has been reported by a number of groups in recent years. To rigorously determine whether flow does indeed have an advantage over batch, a broad range of synthetic photochemical transformations were optimized in both reactor modes and their yields and productivities compared. Surprisingly, yields were essentially identical in all
Reaction Optimization and Mechanism in Maleimide [5 + 2] Photocycloaddition: A Dual Approach Using Tunable UV Lasers and Time-Dependent DFT
作者:David M. E. Davies、Craig Murray、Malcolm Berry、Andrew J. Orr-Ewing、Kevin I. Booker-Milburn
DOI:10.1021/jo062316g
日期:2007.2.1
An in-depth study of the intramolecular [5 + 2] photocycloaddition of maleimides using tunable UV lasers has demonstrated that the peak in quantum yield and rate both occur at wavelengths some 50 nm red shifted from the maxima observed in the UV spectra. A detailed explanation for these findings using time-dependent DFT calculations is presented, and the implications for a previously adopted mechanism
A Practical Flow Reactor for Continuous Organic Photochemistry
作者:Benjamin D. A. Hook、Wolfgang Dohle、Paul R. Hirst、Mark Pickworth、Malcolm B. Berry、Kevin I. Booker-Milburn
DOI:10.1021/jo050705p
日期:2005.9.1
Compact flow reactors have been constructed and optimized to perform continuous organic photochemistry on a large scale. The reactors were constructed from commercially available or customized immersion well equipment combined with LTV-transparent, solvent-resistant fluoropolymer (FEP) tubing. The reactors were assessed using the [2 + 2] photocycloaddition of malemide 1 and 1-hexyne forming the cyclobutene product 2 and the intramolecular [5 + 21 photocycloaddition of 3,4-dimethyl-1-pent-4-enylpyrrole-2,5-dione 3 to form the bicyclic azepine 4. The reactors were shown to be capable of producing > 500 g of 2 and 175 g of 4 in a continuous 24 h processing period. Due to the facile control of irradiation time, the continuous flow reactor was also shown to be superior to a batch reactor for performing a problematic photochemical reaction on a larger scale.