title: Synthesis of Angularly Substituted trans-Fused Decalins through a Metallacycle-Mediated Annulative Cross-Coupling Cascade.
abstract: A convergent coupling reaction is described that enables the stereoselective construction of angularly substituted trans-fused decalins from acyclic precursors. The process builds on our alkoxide-directed titanium-mediated alkyne-alkyne coupling and employs a 1,7-enyne coupling partner. Overall, the reaction is thought to proceed through initial formation of a tetrasusbstituted metallacyclopentadiene, stereoselective intramolecular [4+2] cycloaddition, elimination, isomerization, and regio- and stereoselective protonation. Distinct from our early studies directed at the synthesis of trans-fused hydrindanes, the current annulative coupling reveals an important effect of TMSCl in controlling the final protonation-the event that establishes the stereochemistry of the ring fusion.
authors.affiliation: Department of Chemistry, Dartmouth College, 6128 Burke Laboratory, Hanover, NH, 03755, USA.
authors.forename: Haruki
authors.initials: H
authors.lastname: Mizoguchi
authors.affiliation: Department of Chemistry, Dartmouth College, 6128 Burke Laboratory, Hanover, NH, 03755, USA. glenn.c.micalizio@dartmouth.edu.
authors.forename: Glenn C
authors.identifier: 0000-0002-3408-5570
authors.initials: GC
authors.lastname: Micalizio
mesh_terms: D003500:Cyclization; D061565:Cycloaddition Reaction; D003517:Cyclopentanes / Q000737:chemistry*; D015394:Molecular Structure; D009281:Naphthalenes / Q000138:chemical synthesis* / Q000737:chemistry; D009942:Organometallic Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D014025:Titanium / Q000737:chemistry*
chemical_list: D003517:Cyclopentanes; D009281:Naphthalenes; D009942:Organometallic Compounds; C007229:decalin; D014025:Titanium
keywords: Diels-Alder reactions; carbocycles; cascade reactions; cross-coupling; cycloadditions