One-step route to tricyclic fused 1,2,3,4-tetrahydroisoquinoline systems via the Castagnoli–Cushman protocol

• Aleksandar Pashev,
• Nikola Burdzhiev and
• Elena Stanoeva

Beilstein J. Org. Chem. 2020, 16, 1456–1464, doi:10.3762/bjoc.16.121

• aromatic heterocycles have a low tendency to undergo reactions with cyclic anhydrides, resulting in low to moderate overall yields of the target products [12][27]. Further research by Krasavin et al. on the reactivity of sterically hindered indolenines in reactions with anhydrides 6–9, did not give the

• . Mechanistic pathways for the reaction between cyclic anhydrides and imines. Retrosynthetic analysis of the target compounds. Reaction of 6,7-dimethoxy-3,4-dihydroisoquinoline (18) with anhydrides 5–8. Reagents and conditions: xylene, inert atmosphere, 120 °C, 6 h. Reaction of 1-methyl-3,4-dihydroisoquinoline

Design of indole- and MCR-based macrocycles as p53-MDM2 antagonists

• Constantinos G. Neochoritis,
• Maryam Kazemi Miraki,
• Eman M. M. Abdelraheem,
• Ewa Surmiak,
• Tryfon Zarganes-Tzitzikas,
• Beata Łabuzek,
• Tad A. Holak and
• Alexander Dömling

Beilstein J. Org. Chem. 2019, 15, 513–520, doi:10.3762/bjoc.15.45

• Discussion Synthesis Based on our previous studies [13], unprotected diamines 3 were reacted in one-step with cyclic anhydrides 4 at rt affording the appropriate α,ω-amino acids 5 in excellent yields (see Supporting Information File 1). Elongated diamines (n = 2–4, 6, 8 and 10) and cyclic anhydrides that

• proposed in this work, based on α,ω-amino acids and an Ugi macrocyclization. Reaction of unprotected diamines 3 with cyclic anhydrides 4 at rt affording α,ω-amino acids 5 in quantitative yields. Ugi macrocyclization in a one-pot fashion and synthesis of diverse indole-based macrocycles. The circle depicts

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• Yo Hiranoi Koji Nakano Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan 10.3762/bjoc.14.255 Abstract The alternating copolymerization of epoxides with cyclic anhydrides (CAs) is a highly diverse

• turnover frequencies ever reported. A variety of epoxides and CAs were also found to be copolymerized successfully by the dinuclear cobalt complex with a high catalytic activity. Keywords: cobalt; copolymerization; cyclic anhydrides; epoxides; polyesters; Introduction Aliphatic polyesters have received

• alternating copolymerization of epoxides with cyclic anhydrides (CAs) is a promising alternative for polyester synthesis [11][12]. A broad range of epoxides and CAs are readily available and can be copolymerized through this method. Therefore, the polymer architectures and properties can be easily controlled

Novel amide-functionalized chloramphenicol base bifunctional organocatalysts for enantioselective alcoholysis of meso-cyclic anhydrides

• Lingjun Xu,
• Shuwen Han,
• Linjie Yan,
• Haifeng Wang,
• Haihui Peng and
• Fener Chen

Beilstein J. Org. Chem. 2018, 14, 309–317, doi:10.3762/bjoc.14.19

• bond donor were developed and evaluated for enantioselective organocatalytic alcoholysis of meso-cyclic anhydrides. These structural diversified organocatalysts were found to induce high enantioselectivity in alcoholysis of anhydrides and was successfully applied to the asymmetric synthesis of (S

• stereocontrol in alcoholytic catalytic asymmetric desymmetrizations of meso-cyclic anhydrides is of special interest [1][2][3][4][5][6][7]. Major families originating from natural products include cinchona alkaloids [8][9][10][11][12][13][14][15][16][17] and proteinogenic α-amino acids such as proline [18][19

• great utility of chloramphenicol base scaffold in industrial production of enantiopure compounds is the synthesis of a precursor of biotin (vitamin H) by the chloramphenicol base-promoted asymmetric methanolysis of meso-cyclic anhydrides [41][42][43]. Despite extensive studies on chloramphenicol-base

Radical-mediated dehydrative preparation of cyclic imides using (NH₄)₂S₂O₈–DMSO: application to the synthesis of vernakalant

• Dnyaneshwar N. Garad,
• Subhash D. Tanpure and
• Santosh B. Mhaske

Beilstein J. Org. Chem. 2015, 11, 1008–1016, doi:10.3762/bjoc.11.113

• convenient one-pot process for the synthesis of miscellaneous cyclic imides in high yields starting from readily available primary amines and cyclic anhydrides. A plausible radical mechanism involving DMSO has been proposed. The application of this facile one-pot imide forming process has been demonstrated

• method to construct the imide functionality is to react the corresponding primary amines with cyclic anhydrides to form amic acids, which are then cyclized using acetic anhydride and sodium acetate in a separate step [26]. Hexamethyldisilazane–zinc chloride has also become one of the most widely used

• a convenient one-pot process for the preparation of structurally diverse cyclic imides starting from readily available primary amines and cyclic anhydrides using APS–DMSO as an efficient and novel dehydrating reagent and its application to a drug synthesis. The scope of the developed protocol was

Copolymerization and terpolymerization of carbon dioxide/propylene oxide/phthalic anhydride using a (salen)Co(III) complex tethering four quaternary ammonium salts

• Jong Yeob Jeon,
• Seong Chan Eo,
• Jobi Kodiyan Varghese and
• Bun Yeoul Lee

Beilstein J. Org. Chem. 2014, 10, 1787–1795, doi:10.3762/bjoc.10.187

• from the resin for use in our daily life. In this work, we demonstrate the complete incorporation of the third monomer of phthalic anhydride (PA) in CO2/PO copolymerizations using catalyst 1. Results and Discussion PO/PA copolymerizations Alternating copolymerizations of epoxides and cyclic anhydrides