Rhodium-Catalyzed Asymmetric Allylic Substitution with Boronic Acid Nucleophiles
摘要:
An enantio-, regio-, and diastereoselective rhodium(I)-catalyzed desymmetrization of a meso-cyclic allylic dicarbonate with organoboronic acid nucleophiles is described. The rhodium(I) catalyst formed in situ from [Rh(cod)OH](2) and Xyl-P-PHOS allowed the S(N)2' allylic substitution product to be obtained with a range of arylboronic acids in enantiomeric excesses of up to 92% with regioselectivities of up to > 20:1.
Palladium(0)-catalyzedallylation of imidazoles, 6-methyluracil, 2-pyrimidinone, and Meldrum's acid with cyclopentadiene monoepoxide and cis-cyclopentene-3,5-diol mono and dicarbonate is described.
Rhodium-Catalyzed Asymmetric Allylic Substitution with Boronic Acid Nucleophiles
作者:Frederic Menard、Timothy M. Chapman、Chris Dockendorff、Mark Lautens
DOI:10.1021/ol061777l
日期:2006.9.1
An enantio-, regio-, and diastereoselective rhodium(I)-catalyzed desymmetrization of a meso-cyclic allylic dicarbonate with organoboronic acid nucleophiles is described. The rhodium(I) catalyst formed in situ from [Rh(cod)OH](2) and Xyl-P-PHOS allowed the S(N)2' allylic substitution product to be obtained with a range of arylboronic acids in enantiomeric excesses of up to 92% with regioselectivities of up to > 20:1.
Ligand-Controlled Selectivity in the Desymmetrization of <i>meso</i> Cyclopenten-1,4-diols via Rhodium(I)-Catalyzed Addition of Arylboronic Acids
作者:Frederic Menard、David Perez、Daniela Sustac Roman、Timothy M. Chapman、Mark Lautens
DOI:10.1021/jo100391e
日期:2010.6.18
a Rh-catalyzed asymmetric allylic substitution. Depending on the type of ligand used, each of two regioisomeric products can be obtained in good yield and excellent enantioselectivity. Under rhodium(I) catalysis, bisphosphine P-Phos ligands form trans-1,2-arylcyclopentenols as the major product, whereas Segphos ligands lead predominantly to trans-1,4-arylcyclopentenols.