5 research outputs found
Oxa- and Azacycle Formation via Migrative Cyclization of Sulfonylalkynol and Sulfonylalkynamide with N‑Heterocyclic Carbene
An N-heterocyclic carbene promotes
cyclization of sulfonylalkynols
and sulfonylalkynamides that accompanies 1,2-migration of the sulfonyl
groups. This reaction provides a novel access to oxa- and azacycles
possessing a pendent vinyl sulfone functionality, which, in turn,
is amenable for further transformations
Oxa- and Azacycle Formation via Migrative Cyclization of Sulfonylalkynol and Sulfonylalkynamide with N‑Heterocyclic Carbene
An N-heterocyclic carbene promotes
cyclization of sulfonylalkynols
and sulfonylalkynamides that accompanies 1,2-migration of the sulfonyl
groups. This reaction provides a novel access to oxa- and azacycles
possessing a pendent vinyl sulfone functionality, which, in turn,
is amenable for further transformations
Enhanced Rate and Selectivity by Carboxylate Salt as a Basic Cocatalyst in Chiral N‑Heterocyclic Carbene-Catalyzed Asymmetric Acylation of Secondary Alcohols
The rate and enantioselectivity
of chiral NHC-catalyzed asymmetric
acylation of alcohols with an adjacent H-bond donor functionality
are remarkably enhanced in the presence of a carboxylate cocatalyst.
The degree of the enhancement is correlated with the basicity of the
carboxylate. With a cocatalyst and a newly developed electron-deficient
chiral NHC, kinetic resolution and desymmetrization of cyclic diols
and amino alcohols were achieved with extremely high selectivity (up
to <i>s</i> = 218 and 99% ee, respectively) at a low catalyst
loading (0.5 mol %). This asymmetric acylation is characterized by
a unique preference for alcohols over amines, which are not converted
into amides under the reaction conditions
Enhanced Rate and Selectivity by Carboxylate Salt as a Basic Cocatalyst in Chiral N‑Heterocyclic Carbene-Catalyzed Asymmetric Acylation of Secondary Alcohols
The rate and enantioselectivity
of chiral NHC-catalyzed asymmetric
acylation of alcohols with an adjacent H-bond donor functionality
are remarkably enhanced in the presence of a carboxylate cocatalyst.
The degree of the enhancement is correlated with the basicity of the
carboxylate. With a cocatalyst and a newly developed electron-deficient
chiral NHC, kinetic resolution and desymmetrization of cyclic diols
and amino alcohols were achieved with extremely high selectivity (up
to <i>s</i> = 218 and 99% ee, respectively) at a low catalyst
loading (0.5 mol %). This asymmetric acylation is characterized by
a unique preference for alcohols over amines, which are not converted
into amides under the reaction conditions
Enhanced Rate and Selectivity by Carboxylate Salt as a Basic Cocatalyst in Chiral N‑Heterocyclic Carbene-Catalyzed Asymmetric Acylation of Secondary Alcohols
The rate and enantioselectivity
of chiral NHC-catalyzed asymmetric
acylation of alcohols with an adjacent H-bond donor functionality
are remarkably enhanced in the presence of a carboxylate cocatalyst.
The degree of the enhancement is correlated with the basicity of the
carboxylate. With a cocatalyst and a newly developed electron-deficient
chiral NHC, kinetic resolution and desymmetrization of cyclic diols
and amino alcohols were achieved with extremely high selectivity (up
to <i>s</i> = 218 and 99% ee, respectively) at a low catalyst
loading (0.5 mol %). This asymmetric acylation is characterized by
a unique preference for alcohols over amines, which are not converted
into amides under the reaction conditions