.alpha.-Amino carbanions. Preparation, metalation, and alkylation of enamidines. Synthesis of piperidine and pyrrolidine natural products and homologation of carbonyl compounds
Synthesis of enantiomerically pure fire ant venom alkaloids: Solenopsins and isosolenopsins A, B and C
作者:H. M. T. Bandara Herath、N. P. Dhammika Nanayakkara
DOI:10.1002/jhet.5570450112
日期:2008.1
Concise and efficient methods for the synthesis of enantiomers of fireantvenomalkaloidssolenopsin and isosolenopsin A, B, and C are described. These syntheses are based on diastereoselective electrophilic substitution of enatiomerically-pure α-lithiated 2-alkylpiperidine.
The fire ant venom alkaloid (′)-solenopsin A was prepared in 4 steps (34%) starting from the N-phenyl-2-undecyl piperidine (1c). The key step in this synthesis involved the dearomatization of the phenyl group of N-phenyl-2-methyl-6-undecyl-piperidine (9c), which was carried out under Birch conditions.
Regioselective α-Phosphonylation of Unprotected Alicyclic Amines
作者:Bowen Li、Fuchao Yu、Weijie Chen、Daniel Seidel
DOI:10.1021/acs.orglett.4c02037
日期:2024.7.19
Unprotected alicyclic amines undergo α-C–H bond phosphonylation via a two-stage one-pot process involving the oxidation of amine-derived lithium amides with simple ketone oxidants, generating transient imines which are then captured with phosphites or phosphine oxides. Amines with an existing α-substituent undergo regioselective α′-phosphonylation. Amine α-arylation and α′-phosphonylation can be combined