title: Regioselective Synthesis of Polyheterohalogenated Naphthalenes via the Benzannulation of Haloalkynes.
abstract: Independent control of halide substitution at six of the seven naphthalene positions of 2-arylnaphthalenes is achieved through the regioselective benzannulation of chloro-, bromo-, and iodoalkynes. The modularity of this approach is demonstrated through the preparation of 44 polyheterohalogenated naphthalene products, most of which are difficult to access through known naphthalene syntheses. The outstanding regioselectivity of the reaction is both predictable and proven unambiguously by single-crystal X-ray diffraction for many examples. This synthetic method enables the rapid preparation of complex aromatic systems poised for further derivatization using established cross-coupling methods. The power and versatility of this approach makes substituted naphthalenes highly attractive building blocks for new organic materials and diversity-oriented synthesis.
authors.affiliation: Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York, 14853-1301 (USA).
authors.forename: Dan
authors.initials: D
authors.lastname: Lehnherr
authors.affiliation: Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York, 14853-1301 (USA).
authors.forename: Joaquin M
authors.initials: JM
authors.lastname: Alzola
authors.affiliation: Department of Chemistry and Chemical Biology, X-ray Crystallography Laboratory, Cornell University, Ithaca, New York, 14853-1301 (USA).
authors.forename: Emil B
authors.initials: EB
authors.lastname: Lobkovsky
authors.affiliation: Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York, 14853-1301 (USA). wdichtel@cornell.edu.
authors.forename: William R
authors.initials: WR
authors.lastname: Dichtel
keywords: benzannulation; cycloaddition; halogenation; polycyclic aromatic hydrocarbons; reaction mechanisms