Premium
Regioselectivity Control in the Metal‐Catalyzed Functionalization of γ‐Allenols, Part 2: Theoretical Study
Author(s) -
Alcaide Benito,
Almendros Pedro,
Martínez del Campo Teresa,
Soriano Elena,
MarcoContelles José L.
Publication year - 2009
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200802035
Subject(s) - regioselectivity , enantiopure drug , chemistry , palladium , catalysis , amide , lanthanum , lanthanide , combinatorial chemistry , metal , reactivity (psychology) , computational chemistry , organic chemistry , enantioselective synthesis , medicine , ion , alternative medicine , pathology
Calculating cyclization : Theoretical work directed towards the elucidation of the mechanisms of the gold‐, palladium‐, and lanthanum‐catalyzed oxycyclizations (5‐ exo versus 6‐ endo versus 7‐ endo ) of γ‐allenols has been pursued in close relationship with the experimental study (Part 1, accompanying paper) and has corroborated the bench results to provide a complete study of the reactivity of γ‐allenols under different metal‐catalyzed conditions.The gold‐, palladium‐ and lanthanum‐catalyzed oxycyclization reactions of azetidin‐2‐one‐tethered γ‐allenol derivatives to a variety of fused enantiopure tetrahydrofurans, dihydropyrans, and tetrahydrooxepines have been developed experimentally (Part 1, accompanying paper). The mechanisms of these regiocontrolled metal‐catalyzed heterocyclization reactions have now been computationally explored at the DFT level (Part 2). The energies of the reaction intermediates and transition states for different possible pathways have been calculated in various model systems very close to the real system. Additionally, we selected the La[N(SiH 3 ) 2 ] 3 complex to simulate the lanthanide amide precatalyst species. The agreement of theoretically predicted and experimentally observed selectivities is very good in all cases