51498-55-6Relevant academic research and scientific papers
Two-Step Catalytic Transformation of N-Benzyllactams to Alkaloids (±)-Solenopsin, (±)-Solenopsin A, and (+)-Julifloridine
Ou, Wei,Lu, Guang-Sheng,An, Dong,Han, Feng,Huang, Pei-Qiang
, p. 52 - 56 (2020)
We report herein that the Ir and CuI bis-metal catalyzed reductive alkynylation of amides, a method that we developed previously, can be extended to 6-, 7-, and 8-membered lactams. The catalytic reductive alkynylation of 6-methyl-2-piperidinone
Aromatic Aza-Claisen Rearrangement of Arylpropargylammonium Salts Generated in situ from Arynes and Tertiary Propargylamines
Han, Lu,Li, Sheng-Jun,Zhang, Xue-Ting,Tian, Shi-Kai
supporting information, p. 3091 - 3097 (2021/01/21)
The charge-accelerated aza-Claisen rearrangement of ammonium salts serves as a key step in the construction of complex nitrogen-containing molecules. However, much less attention has been paid to the aromatic aza-Claisen rearrangement than to the aliphatic one. Herein, we report an unprecedented aromatic aza-Claisen rearrangement of arylpropargylammonium salts, generated in situ from arynes and tertiary propargylamines, delivering structurally diverse 2-propargylanilines in moderate to good yields with high regioselectivity. This rearrangement proceeds in the absence of strong bases or transition metals, is compatible with moisture and air, tolerates a wide variety of functional groups, and is amenable to forming 11- to 13-membered heterocycles with a triple bond. The 2-propargylaniline products were treated with aluminum chloride in ethanol to afford multisubstituted indoles in moderate to excellent yields. Finally, a series of deuterium-labeling experiments was performed to elucidate the reaction mechanism.
First synthesis of medium-sized ring allenyl lactams
Perscheid, Moritz,Schollmeyer, Dieter,Nubbemeyer, Udo
experimental part, p. 5250 - 5253 (2011/11/12)
Medium-sized lactams bearing an axially chiral allene unit have been synthesized by using an aza-ketene Claisen rearrangement. Starting from 2-alkynylpiperidines or 2-alkynylazepines, ring enlargement enabled the highly diastereoselective formation of 10-
A Three-Component, One-Pot Synthesis of Indolizidines and Related Heterocycles Via the [3+2] Cycloaddition of Nonstabilized Azomethine Ylides
Pearson, William H.,Stoy, Patrick,Mi, Yuan
, p. 1919 - 1939 (2007/10/03)
Nonstabilized azomethine ylides (i.e. those bearing only hydrogens or alkyl groups) can be generated from (2-azaallyl)stannanes and (2-azaallyl)silanes through an intramolecular N-alkylation/demetalation cascade. The resulting ylides undergo [3+2] cycloaddition with electron-poor or electron-rich dipolarophiles yielding indolizidines and related 1-aza[m.3.0]bicycloalkane systems in good yield. An in situ protocol allows for a one-pot, three-component synthesis of indolizidines. The (2-azaallyl) stannanes tolerate enolizable hydrogens in these cycloadditions, while (2-azaallyl)silanes do not. The mechanism of the cycloaddition cascade is clarified by a series of control experiments. The same (2-azaallyl)stannanes may be transmetalated by n-butyllithium to generate 2-azaallyl-lithiums, which also may undergo a [3+2] cycloaddition/N-alkylation cascade to form indolizidines.
Alkynylation of Thiolactams. New Synthesis of α-Substituted Pyrrolidine and Piperidine Alkaloids
Takahata, Hiroki,Takahashi, Koichi,Wang, Eng-Chi,Yamazaki, Takao
, p. 1211 - 1214 (2007/10/02)
Alkynylation of S-alkylthioamidium salts of thiolactams with lithium acetylides followed by reduction with LiAlH4 provided α-alkynylazacycloalkanes, which on reduction, or hydroboration followed by oxidation, gave α-substituted pyrrolidine and piperidine alkaloids.
