2766-43-0Relevant articles and documents
Stereoselective synthesis of (-)-α-kainic acid and (+)-α-allokainic acid via trimethylstannyl-mediated radical carbocyclization and oxidative destannylation
Hanessian, Stephen,Ninkovic, Sacha
, p. 5418 - 5424 (1996)
(-)-α-Kainic acid (1) and its C4 epimer (+)-α-allokainic acid (2) have been prepared from L-serine. The requisite stereochemical array in (-)-α-kainic acid (1) was introduced using a trimethylstannyl radical carbocyclization of a diene, which gave the 2,3-trans/3,4-cis and 2,3-trans/3,4-trans componnds in a 2.8:1 ratio and in high yield. The destannylation of the trisubstituted pyrrolidine nucleus was achieved via an oxidative cleavage of the C-Sn bond with ceric ammonium nitrate. This provided a dimethyl acetal that was further transformed into the intended α-kainic acid. When the same radical carbocyclization was attempted on a triene, the 2,3-trans/3,4-trans and the 2,3-trans/3,4-cis adducts were obtained in a 2.5:1 ratio, respectively. This approach was used to synthesize (+)-α-allokainic acid.
Simple and efficient procedure for a multigram synthesis of both trans - And cis -1-Amino-2-(trifluoromethyl)cyclopropane-1-carboxylic Acid
Artamonov, Olexiy S.,Mykhailiuk, Pavel K.,Voievoda, Nataliia M.,Volochnyuk, Dmitry M.,Komarov, Igor V.
, p. 443 - 446 (2010)
A simple and efficient procedure for the multigram synthesis of both (±)-trans- and (±)-cis-1-amino-2-(trifluoromethyl)cyclopropane-1- carboxylic acid was developed. The key step of the synthesis is the addition of 1-diazo-2,2,2-trifluoroethane to methyl 2-[(tert-butoxycarbonyl)amino]acrylate, followed by thermal decomposition of the resulting pyrazoline. Gram quantities of trans- and cis-1-amino-2-(trifluoromethyl)cyclopropane-1-carboxylic acid were easily prepared from l-serine in one synthetic run. Georg Thieme Verlag Stuttgart - New York.
Efficient Hydro- and Organogelation by Minimalistic Diketopiperazines Containing a Highly Insoluble Aggregation-Induced, Blue-Shifted Emission Luminophore**
Molkenthin, Martin,Nachtsheim, Boris J.,Nau, Werner M.
supporting information, p. 16488 - 16497 (2021/10/25)
We report the synthesis, gelation abilities and aggregation-induced, blue-shifted emission (AIBSE) properties of two minimalistic diketopiperazine-based gelators. Despite containing a highly insoluble luminophore that makes up more than half of their respective molecular masses, efficient hydrogelation by multiple stimuli for one and efficient organogelation for the other compound are reported. Insights into the aggregation and gelation properties were gained through examination of the photophysical and material properties of selected gels, which are representative of the different modes of gelation. The synthesis of the gelators is highly modular and based on readily available amino acid building blocks, allowing the efficient and rapid diversification of these core structures and fine-tuning of gel properties.
Late-Stage Intermolecular Allylic C-H Amination
Clark, Joseph R.,Dixon, Charlie F.,Feng, Kaibo,Han, Wei,Ide, Takafumi,Koch, Vanessa,Teng, Dawei,Wendell, Chloe I.,White, M. Christina
supporting information, p. 14969 - 14975 (2021/10/01)
Allylic amination enables late-stage functionalization of natural products where allylic C-H bonds are abundant and introduction of nitrogen may alter biological profiles. Despite advances, intermolecular allylic amination remains a challenging problem due to reactivity and selectivity issues that often mandate excess substrate, furnish product mixtures, and render important classes of olefins (for example, functionalized cyclic) not viable substrates. Here we report that a sustainable manganese perchlorophthalocyanine catalyst, [MnIII(ClPc)], achieves selective, preparative intermolecular allylic C-H amination of 32 cyclic and linear compounds, including ones housing basic amines and competing sites for allylic, ethereal, and benzylic amination. Mechanistic studies support that the high selectivity of [MnIII(ClPc)] may be attributed to its electrophilic, bulky nature and stepwise amination mechanism. Late-stage amination is demonstrated on five distinct classes of natural products, generally with >20:1 site-, regio-, and diastereoselectivity.