title: Dehydrative fragmentation of 5-hydroxyalkyl-1H-tetrazoles: a mild route to alkylidenecarbenes.
abstract: The development of a mild, base-free method for the generation of alkylidenecarbenes is reported. Treatment of 5-hydroxyalkyl-1H-tetrazoles with carbodiimides generates products arising from the 1,2-rearrangement or [1,5]-C-H bond insertion of a putative alkylidenecarbene. Formation of this divalent intermediate is proposed to occur by way of a tetraazafulvene, which undergoes extrusion of 2 mol of dinitrogen. Details of this methodology, its application to the synthesis of combretastatin A-4, and an improved route to 5-hydroxyalkyl-1H-tetrazoles are described.
authors.affiliation: Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, United States. wardropd@uic.edu
authors.forename: Duncan J
authors.initials: DJ
authors.lastname: Wardrop
authors.forename: John P
authors.initials: JP
authors.lastname: Komenda
mesh_terms: D020650:Combinatorial Chemistry Techniques; D008697:Methane / Q000031:analogs & derivatives / Q000737:chemistry; D015394:Molecular Structure; D013267:Stilbenes / Q000138:chemical synthesis* / Q000737:chemistry; D013777:Tetrazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D013267:Stilbenes; D013777:Tetrazoles; C030011:carbene; C045574:1H-tetrazole; C058728:fosbretabulin; D008697:Methane