Regioselectivity in the Palladium-Catalyzed Addition of Carbon Nucleophiles to Dihydropyran Derivatives
摘要:
The regioselectivity of Pd-catalyzed malonate or sulfonylacetate addition to dihydropyran derivatives is highly dependent upon the substitution pattern of the dihydropyran nucleus and is governed by electronic, rather than steric factors. In certain instances, subtle steric features also play a role in controlling regioselectivity by altering the conformation of the intermediate eta(3)-allyl Pd-complex.
Total Synthesis of the Postulated Structure of Fulicineroside
作者:Ruben Bartholomäus、Fabian Dommershausen、Markus Thiele、Narayan S. Karanjule、Klaus Harms、Ulrich Koert
DOI:10.1002/chem.201204545
日期:2013.6.3
A totalsynthesis of the proposed structures of fulicineroside and its aglycone fulicinerine is reported. The tetrasubstituted dibenzofuran substructure was accessible either through a Pd‐mediated ortho‐metalation or by an Ir‐catalyzed meta‐borylation. The synthesis of the β,β,α‐linked trisaccharide consisting of D‐olivose, L‐rhodinose, and L‐rhamnose was challenged by the unprecedented β‐linked rhodinose