16 research outputs found
Stille Coupling of an Aziridinyl Stannatrane
An aziridinyl stannatrane <b>8</b> couples with aryl or alkenyl
halides RX under modified Stille conditions to afford substituted
aziridines. Efficient coupling at room temperature is possible in
the best examples in the presence of (<sup><i>t</i></sup>Bu<sub>3</sub>P)<sub>2</sub>Pd and CuOP(O)Ph<sub>2</sub> (CuDPP)
Enantioselective Synthesis of Cocaine C-1 Analogues using Sulfinimines (<i>N</i>-Sulfinyl Imines)
The first examples of cocaine analogues having substituents
(methyl,
ethyl, <i>n</i>-propyl, <i>n</i>-pentyl, and phenyl)
at the C-1 position of the cocaine tropane skeleton were prepared
by heating sulfinimine-derived α,β-unsaturated pyrrolidine
nitrones. In the presence of the Lewis acid Al(O<i><sup>t</sup></i>Bu)<sub>3</sub> the nitrones undergo an intramolecular [3
+ 2] cycloaddition to give tricyclic isoxazolidines that were transformed
in three steps to the cocaine analogues. In the absence of the Lewis
acid, lactams were formed resulting from rearrangement of the nitrone
to an oxaziridine. A novel Pd- and base-promoted rearrangement of
methanesulfonate salts of isoxazolidine to bridge bicyclic[4.2.1]isoxazolidines
was discovered
Enantioselective Synthesis of Cocaine C-1 Analogues using Sulfinimines (<i>N</i>-Sulfinyl Imines)
The first examples of cocaine analogues having substituents
(methyl,
ethyl, <i>n</i>-propyl, <i>n</i>-pentyl, and phenyl)
at the C-1 position of the cocaine tropane skeleton were prepared
by heating sulfinimine-derived α,β-unsaturated pyrrolidine
nitrones. In the presence of the Lewis acid Al(O<i><sup>t</sup></i>Bu)<sub>3</sub> the nitrones undergo an intramolecular [3
+ 2] cycloaddition to give tricyclic isoxazolidines that were transformed
in three steps to the cocaine analogues. In the absence of the Lewis
acid, lactams were formed resulting from rearrangement of the nitrone
to an oxaziridine. A novel Pd- and base-promoted rearrangement of
methanesulfonate salts of isoxazolidine to bridge bicyclic[4.2.1]isoxazolidines
was discovered
Enantioselective Synthesis of Cocaine C-1 Analogues using Sulfinimines (<i>N</i>-Sulfinyl Imines)
The first examples of cocaine analogues having substituents
(methyl,
ethyl, <i>n</i>-propyl, <i>n</i>-pentyl, and phenyl)
at the C-1 position of the cocaine tropane skeleton were prepared
by heating sulfinimine-derived α,β-unsaturated pyrrolidine
nitrones. In the presence of the Lewis acid Al(O<i><sup>t</sup></i>Bu)<sub>3</sub> the nitrones undergo an intramolecular [3
+ 2] cycloaddition to give tricyclic isoxazolidines that were transformed
in three steps to the cocaine analogues. In the absence of the Lewis
acid, lactams were formed resulting from rearrangement of the nitrone
to an oxaziridine. A novel Pd- and base-promoted rearrangement of
methanesulfonate salts of isoxazolidine to bridge bicyclic[4.2.1]isoxazolidines
was discovered
Enantioselective Synthesis of Cocaine C-1 Analogues using Sulfinimines (<i>N</i>-Sulfinyl Imines)
The first examples of cocaine analogues having substituents
(methyl,
ethyl, <i>n</i>-propyl, <i>n</i>-pentyl, and phenyl)
at the C-1 position of the cocaine tropane skeleton were prepared
by heating sulfinimine-derived α,β-unsaturated pyrrolidine
nitrones. In the presence of the Lewis acid Al(O<i><sup>t</sup></i>Bu)<sub>3</sub> the nitrones undergo an intramolecular [3
+ 2] cycloaddition to give tricyclic isoxazolidines that were transformed
in three steps to the cocaine analogues. In the absence of the Lewis
acid, lactams were formed resulting from rearrangement of the nitrone
to an oxaziridine. A novel Pd- and base-promoted rearrangement of
methanesulfonate salts of isoxazolidine to bridge bicyclic[4.2.1]isoxazolidines
was discovered
Enantioselective Synthesis of Cocaine C-1 Analogues using Sulfinimines (<i>N</i>-Sulfinyl Imines)
The first examples of cocaine analogues having substituents
(methyl,
ethyl, <i>n</i>-propyl, <i>n</i>-pentyl, and phenyl)
at the C-1 position of the cocaine tropane skeleton were prepared
by heating sulfinimine-derived α,β-unsaturated pyrrolidine
nitrones. In the presence of the Lewis acid Al(O<i><sup>t</sup></i>Bu)<sub>3</sub> the nitrones undergo an intramolecular [3
+ 2] cycloaddition to give tricyclic isoxazolidines that were transformed
in three steps to the cocaine analogues. In the absence of the Lewis
acid, lactams were formed resulting from rearrangement of the nitrone
to an oxaziridine. A novel Pd- and base-promoted rearrangement of
methanesulfonate salts of isoxazolidine to bridge bicyclic[4.2.1]isoxazolidines
was discovered
Enantioselective Synthesis of Cocaine C-1 Analogues using Sulfinimines (<i>N</i>-Sulfinyl Imines)
The first examples of cocaine analogues having substituents
(methyl,
ethyl, <i>n</i>-propyl, <i>n</i>-pentyl, and phenyl)
at the C-1 position of the cocaine tropane skeleton were prepared
by heating sulfinimine-derived α,β-unsaturated pyrrolidine
nitrones. In the presence of the Lewis acid Al(O<i><sup>t</sup></i>Bu)<sub>3</sub> the nitrones undergo an intramolecular [3
+ 2] cycloaddition to give tricyclic isoxazolidines that were transformed
in three steps to the cocaine analogues. In the absence of the Lewis
acid, lactams were formed resulting from rearrangement of the nitrone
to an oxaziridine. A novel Pd- and base-promoted rearrangement of
methanesulfonate salts of isoxazolidine to bridge bicyclic[4.2.1]isoxazolidines
was discovered