Reaction of novel imide reducing reagents with pyrrolizidinediones

A Facile Preparation of Enecarbamates

“…Reduction of lactams with NaBH 4 in ethanol requires the addition of acid (e.g., HCl or H 2 SO 4 ) to accelerate the reaction and prevent over-reduction via the ring opened aldehyde 8c. Utilization of methanol, excess NaBH 4 , and short reaction times at −4 °C chemoselectively reduces imides without the need for added acid 10a DIBAL reduction of 1-methylglutarimide proved problematic and the hydroxy lactam could only be obtained in modest yield with lithium triethylborohydride (Super Hydride) 10b…”

“…Utilization of methanol, excess NaBH 4 , and short reaction times at −4 °C chemoselectively reduces imides without the need for added acid 10a DIBAL reduction of 1-methylglutarimide proved problematic and the hydroxy lactam could only be obtained in modest yield with lithium triethylborohydride (Super Hydride) 10b …”

Palladium Catalyzed Synthesis of Münchnones from α‐Amidoethers: A Mild Route to Pyrroles

“…The preparation of 1 includes the in situ condensation of aldehydes and amides, the electrochemical oxidation of amides, the reduction of imides or imidates, or the acylation of imines. [2] The coupling of this synthesis with catalytic carbonylation allows the formation of amino acid derivatives, which have various substitutions, in a minimal number of steps and on large scale. [1] While effective, this reaction typically requires high reaction temperatures, high CO pressures (ca.…”

On the synthesis of α-amino sulfoxides

“…Examples of cyclic α-amino sulfoxides include azetidinones 10 15 and 11, 16 both synthesised by sulfide oxidation and aziridines such as 12 17 which was prepared by cyclisation of the amine onto an α-chloro sulfoxide. The only pyrrolidinecontaining α-amino sulfoxide that we are aware of is 13 18 which was obtained by oxidation of the sulfide. Examples of penicillin-like 19 and cephalosporin-like 20 sulfoxides such as 14 and 15 respectively have also been described; both were synthesised by sulfur oxidation.…”