Synthesis of Spirocyclic Cyclobutenes through Desulfinative Spirocyclisation of gem-Bis(triflyl)cyclobutenes |
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Authors: | Shoki Hoshikawa Dr Hikaru Yanai Prof Dr Takashi Matsumoto |
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Institution: | School of Pharmacy, Tokyo University of Pharmacy and Life Sciences 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392 Japan |
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Abstract: | A two-step synthesis of less accessible spirocyclobutene-1,9′-fluorene] compounds from biaryl-alkynes and 2-(2-fluoropyridin-1-ium-1-yl)-1,1-bis((trifluoromethyl)sulfonyl)ethan-1-ide, which serves as a potent precursor for outstandingly electrophilic Tf2C=CH2, has been developed. This synthetic methodology includes selective formation of gem-bis(triflyl)cyclobutenes from biaryl-alkynes and Tf2C=CH2 followed by desulfinative spirocyclisation mediated by 1,1,1,3,3,3-hexafluoroisopropyl alcohol (HFIP). Besides, on the basis of the chameleonic reactivity of sulfone functionality, several derivatisations of triflylated spirocyclobutene-1,9′-fluorene] products have been successfully achieved. |
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Keywords: | cyclization electrophilic substitution fluorine polycycles spiro compounds |
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