title: Indolyne and aryne distortions and nucleophilic regioselectivites.
abstract: Density functional theory computations reproduce the surprisingly high regioselectivities in nucleophilic additions and cycloadditions to 4,5-indolynes and the low regioselectivities in the reactions of 5,6-indolynes. Transition-state distortion energies control the regioselectivities, activating the 5 and 6 positions over the 4 and 7 positions, leading to high preferences for 5- and 6-substituted products from 4,5- and 6,7-indolynes, respectively. Orbital and electrostatic interactions have only minor effects, producing low regioselectivities in the reactions of 5,6-indolynes. The distortion model predicts high regioselectivities with 6,7-indolynes; these have been verified experimentally. The regioselectivities found with other arynes are explained on the basis of distortion energies that are reflected in reactant geometries.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, Los Angeles, California 90095, USA.
authors.forename: Paul H-Y
authors.initials: PH
authors.lastname: Cheong
authors.forename: Robert S
authors.initials: RS
authors.lastname: Paton
authors.forename: Sarah M
authors.initials: SM
authors.lastname: Bronner
authors.forename: G-Yoon J
authors.initials: GY
authors.lastname: Im
authors.forename: Neil K
authors.initials: NK
authors.lastname: Garg
authors.forename: K N
authors.initials: KN
authors.lastname: Houk
mesh_terms: D006841:Hydrocarbons, Aromatic / Q000737:chemistry*; D007211:Indoles / Q000737:chemistry; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D011789:Quantum Theory; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D006841:Hydrocarbons, Aromatic; D007211:Indoles