title: Alkenyl Isocyanide Conjugate Additions: A Rapid Route to γ-Carbolines.
abstract: Isocyanides are exceptional building blocks, the wide deployment of which in multicomponent and metal-insertion reactions belies their limited availability. The first conjugate addition/alkylation to alkenyl isocyanides is described, which addresses this deficiency. An array of organolithiums, magnesiates, enolates, and metalated nitriles add conjugately to β- and β,β-disubstituted arylsulfonyl alkenyl isocyanides to rapidly assemble diverse isocyanide scaffolds. The intermediate metalated isocyanides are efficiently trapped with electrophiles to generate substituted isocyanides incorporating contiguous tri- and tetra-substituted centers. The substituted isocyanides are ideally functionalized for elaboration into synthetic targets as illustrated by the three-step synthesis of γ-carboline N-methyl ingenine B.
authors.affiliation: Department of Chemistry, Drexel University, 32 South 32nd St., Philadelphia, PA, 19104, USA.
authors.forename: Sergiy V
authors.initials: SV
authors.lastname: Chepyshev
authors.affiliation: Departmento de Química, Centro de Investigación y de Estudios Avanzados (Cinvestav), Av. Instituto Politécnico Nacional 2508, Ciudad de México, 07360, México.
authors.forename: J Armando
authors.initials: JA
authors.lastname: Lujan-Montelongo
authors.affiliation: Department of Chemistry, Drexel University, 32 South 32nd St., Philadelphia, PA, 19104, USA.
authors.forename: Allen
authors.initials: A
authors.lastname: Chao
authors.affiliation: Department of Chemistry, Drexel University, 32 South 32nd St., Philadelphia, PA, 19104, USA.
authors.forename: Fraser F
authors.identifier: 0000-0002-9637-0246
authors.initials: FF
authors.lastname: Fleming
mesh_terms: D000475:Alkenes / Q000737:chemistry*; D002243:Carbolines / Q000138:chemical synthesis* / Q000737:chemistry; D003486:Cyanides / Q000737:chemistry*; D015394:Molecular Structure
chemical_list: D000475:Alkenes; D002243:Carbolines; D003486:Cyanides; C055572:gamma-carboline
keywords: conjugate addition; isocyanides; organometallics; synthetic methods; γ-carbolines