5 research outputs found
Nitroepoxides as Versatile Precursors to 1,4-Diamino Heterocycles
Nitroepoxides
are easily transformed into 1,4-diamino heterocycles
such as quinoxalines and pyrazines by treatment with 1,2-benzenediamines
and ammonia, respectively. Additionally, related saturated heterocycles,
such as piperazines and tetrahydroquinoxalines, can be accessed by
treatment with 1,2-diamines and a reducing agent. These transformations
are efficient, provide access privileged, bioactive structures, and
produce minimal waste
Dynamic Kinetic Asymmetric Ring-Opening/Reductive Amination Sequence of Racemic Nitroepoxides with Chiral Amines: Enantioselective Synthesis of Chiral Vicinal Diamines
We
report a highly diastereoselective synthesis of vicinal diamines by
the treatment of nitroepoxides with primary amines and then a reducing
agent. When using a chiral primary amine, racemic nitroepoxides are
transformed into chiral diamines as a single enantiomers (>95:5
er) through a dynamic kinetic asymmetric transformation (DYKAT). The
overall process is a one-pot procedure combining the exposure of nitroepoxides
to chiral amines to afford diastereomeric mixtures of aminoimines
and subsequent stereoselective imine reduction
Dynamic Kinetic Asymmetric Ring-Opening/Reductive Amination Sequence of Racemic Nitroepoxides with Chiral Amines: Enantioselective Synthesis of Chiral Vicinal Diamines
We
report a highly diastereoselective synthesis of vicinal diamines by
the treatment of nitroepoxides with primary amines and then a reducing
agent. When using a chiral primary amine, racemic nitroepoxides are
transformed into chiral diamines as a single enantiomers (>95:5
er) through a dynamic kinetic asymmetric transformation (DYKAT). The
overall process is a one-pot procedure combining the exposure of nitroepoxides
to chiral amines to afford diastereomeric mixtures of aminoimines
and subsequent stereoselective imine reduction
Synthetic Studies on the Preparation of Alanyl Epoxysulfones as Cathepsin Cysteine Protease Electrophilic Traps
A Darzens
reaction between <i>tert</i>-butoxycarbonyl
alaninal and chloromethyl phenyl sulfone afforded chlorohydrins, which
were converted into epoxysulfones by reaction with sodium <i>tert</i>-butoxide. Epoxysulfone <b>10</b> and chloroketone <b>14</b> derived from chlorohydrins by oxidation proved to be inhibitors
of cathepsins H, S, and C as determined by competitive activity-based
protein profiling
Radical Mechanism in the Elimination of 2-Arylsulfinyl Esters
The mechanism of the dehydrosulfenylation of 2-arylsulfinyl
esters
was investigated. The reaction was found to follow a homolytic cleavage
mechanism as verified by electrospray ionization tandem mass spectrometry
and experimental work. Rearranged sulfoxides are obtained as byproduct
during the elimination reaction