6 research outputs found
Isolable Analogues of the Breslow Intermediate Derived from Chiral Triazolylidene Carbenes
Since Breslow’s initial report on the thiamine
mode of action,
the study of catalytic acyl carbanion processes has been an area of
immense interest. With the advent of azolylidene catalysis, a plethora
of reactivtiy has been harnessed, but the crucial nucleophilic intermediate
proposed by Breslow had never been isolated or fully characterized.
Herein, we report the isolation and full characterization of nitrogen
analogues of the Breslow intermediate. Both stable and catalytically
relevant, these species provide a model system for the study of acyl
carbanion and homoenolate processes catalyzed by triazolylidene carbenes
Isolable Analogues of the Breslow Intermediate Derived from Chiral Triazolylidene Carbenes
Since Breslow’s initial report on the thiamine
mode of action,
the study of catalytic acyl carbanion processes has been an area of
immense interest. With the advent of azolylidene catalysis, a plethora
of reactivtiy has been harnessed, but the crucial nucleophilic intermediate
proposed by Breslow had never been isolated or fully characterized.
Herein, we report the isolation and full characterization of nitrogen
analogues of the Breslow intermediate. Both stable and catalytically
relevant, these species provide a model system for the study of acyl
carbanion and homoenolate processes catalyzed by triazolylidene carbenes
Isolable Analogues of the Breslow Intermediate Derived from Chiral Triazolylidene Carbenes
Since Breslow’s initial report on the thiamine
mode of action,
the study of catalytic acyl carbanion processes has been an area of
immense interest. With the advent of azolylidene catalysis, a plethora
of reactivtiy has been harnessed, but the crucial nucleophilic intermediate
proposed by Breslow had never been isolated or fully characterized.
Herein, we report the isolation and full characterization of nitrogen
analogues of the Breslow intermediate. Both stable and catalytically
relevant, these species provide a model system for the study of acyl
carbanion and homoenolate processes catalyzed by triazolylidene carbenes
Enantioselective Rhodium-Catalyzed Isomerization of 4‑Iminocrotonates: Asymmetric Synthesis of a Unique Chiral Synthon
An
enantioselective isomerization of 4-iminocrotonates catalyzed
by a rhodiumÂ(I)/phosphoramidite complex is described. This reaction
uses widely available amines to couple with 4-oxocrotonate to provide
a convenient access to a central chiral building block in good yield
and high enantioselectivity. Although the mechanism of this new transformation
remains unclear, both Rh and the phosphoramidite play a central role
Divergent Synthesis of Pyrone Diterpenes via Radical Cross Coupling
A divergent strategy for assembling
pyrone diterpenes is presented.
Capitalizing on the unique stereo- and chemoselectivity features of
radical-based chemistry, the core decalin of these structures is efficiently
forged using an electrochemically assisted oxidative radical polycyclization
while key peripheral substituents are appended using decarboxylative
radical cross couplings. In this way, access to four natural products
(subglutinols A/B, higginsianin A, and sesquicillin A) is achieved
in a concise and stereocontrolled fashion that is modular and amenable
to future medicinal chemistry explorations
Divergent Synthesis of Pyrone Diterpenes via Radical Cross Coupling
A divergent strategy for assembling
pyrone diterpenes is presented.
Capitalizing on the unique stereo- and chemoselectivity features of
radical-based chemistry, the core decalin of these structures is efficiently
forged using an electrochemically assisted oxidative radical polycyclization
while key peripheral substituents are appended using decarboxylative
radical cross couplings. In this way, access to four natural products
(subglutinols A/B, higginsianin A, and sesquicillin A) is achieved
in a concise and stereocontrolled fashion that is modular and amenable
to future medicinal chemistry explorations