From time to time, we see phase-transfer catalysis applied to radical reactions. Usually the phase-transfer catalyst transfers a radical initiator such as persulfate that undergoes homolytic scission into 2 “sulfate” radical anions. In US Patent 9,237,745, the phase-transfer catalyst transfers dithionite to the organic phase (MTBE) which in turn reacts with the heptafluoroisopropyl iodide to form iodine radical and the perfluoroisopropyl radical. The perfluoroisoproyl radical adds to the aniline in the para position and eliminates a hydrogen radical (forming HI presumably neutralized by the bicarbonate to prevent protonation of the aniline nitrogen) to produce the desired product.
This patent illustrates the concept that if we need to transfer an anion to an organic phase, even if it is to initiate a radical reaction, phase-transfer catalysis is an effective method of choice.
To assure that you achieve the highest performance in your process development programs for radical initiated reactions, strong base reactions, nucleophilic substitutions, oxidations or reductions, now contact Marc Halpern of PTC Organics Inc. to explore whether phase-transfer catalysis will help you and your company be more competitive. The job you save through increased profitability and R&D efficiency may be your own.
About Marc Halpern
Dr. Halpern is founder and president of PTC Organics, Inc., the only company dedicated exclusively to developing low-cost high-performance green chemistry processes for the manufacture of organic chemicals using Phase Transfer Catalysis. Dr. Halpern has innovated PTC breakthroughs for pharmaceuticals, agrochemicals, petrochemicals, monomers, polymers, flavors & fragrances, dyes & pigments and solvents. Dr. Halpern has provided PTC services on-site at more than 260 industrial process R&D departments in 37 countries and has helped chemical companies save > $200 million. Dr. Halpern co-authored five books including the best-selling “Phase-Transfer Catalysis: Fundamentals, Applications and Industrial Perspectives” and has presented the 2-day course “Practical Phase-Transfer Catalysis” at 50 locations in the US, Europe and Asia.
Dr. Halpern founded the journal “Industrial Phase-Transfer Catalysis” and “The PTC Tip of the Month” enjoyed by 2,100 qualified subscribers, now beyond 130 issues. In 2014, Dr. Halpern is celebrating his 30th year in the chemical industry, including serving as a process chemist at Dow Chemical, a supervisor of process chemistry at ICI, Director of R&D at Sybron Chemicals and founder and president of PTC Organics Inc. (15 years) and PTC Communications Inc. (20 years). Dr. Halpern also co-founded PTC Interface Inc. in 1989 and PTC Value Recovery Inc. in 1999. His academic breakthroughs include the PTC pKa Guidelines, the q-value for quat accessibility and he has achieved industrial PTC breakthroughs for a dozen strong base reactions as well as esterifications, transesterifications, epoxidations and chloromethylations plus contributed to more than 100 other industrial PTC process development projects.
Dr. Halpern has dedicated his adult life to his family and to phase-transfer catalysis (in that order!).