A synthetic route to 1,4-disubstituted tetrahydro-β-carbolines and tetrahydropyranoindoles via ring-opening/Pictet–Spengler reaction of aziridines and epoxides with indoles/aldehydes

2020 ◽  
Vol 18 (2) ◽  
pp. 272-287 ◽  
Author(s):  
Imtiyaz Ahmad Wani ◽  
Gaurav Goswami ◽  
Sahid Sk ◽  
Abhijit Mal ◽  
Masthanvali Sayyad ◽  
...  

A route to 1,4-disubstituted tetrahydro-β-carbolines and tetrahydropyrano[3,4-b]indoles in high yields and stereoselectivity via SN2-type ring opening/Pictet–Spengler reaction of aziridines and epoxides with indoles is described.

2018 ◽  
Vol 54 (62) ◽  
pp. 8583-8586 ◽  
Author(s):  
Sajan Pradhan ◽  
Chandan Kumar Shahi ◽  
Aditya Bhattacharyya ◽  
Manas K. Ghorai

A novel synthetic route to 3-spiropiperidino indoleninesviaLewis acid catalyzed SN2-type ring opening of activated aziridines with 1H-indoles followed by Pd-catalyzed spirocyclization with propargyl carbonates in high yields (up to 88%) with excellent diastereo- and enantiospecificity (dr >99 : 1; ee up to >99) is reported.


ACS Omega ◽  
2018 ◽  
Vol 3 (12) ◽  
pp. 17562-17572 ◽  
Author(s):  
Gaurav Goswami ◽  
Navya Chauhan ◽  
Abhijit Mal ◽  
Subhomoy Das ◽  
Mowpriya Das ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3366
Author(s):  
Antonio Arcadi ◽  
Andrea Calcaterra ◽  
Giancarlo Fabrizi ◽  
Andrea Fochetti ◽  
Antonella Goggiamani ◽  
...  

An alternative Au(I)-catalyzed synthetic route to functionalized 1,2-dihydroquinolines is reported. This novel approach is based on the use of N-ethoxycarbonyl protected-N-propargylanilines as building blocks that rapidly undergo the IMHA reaction affording the 6-endo cyclization product in good to high yields. In the presence of N-ethoxycarbonyl-N-propargyl-meta-substituted anilines, the regiodivergent cyclization at the ortho-/para-position is achieved by the means of catalyst fine tuning.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4265
Author(s):  
Victor Carramiñana ◽  
Ana M. Ochoa de Ochoa de Retana ◽  
Francisco Palacios ◽  
Jesús M. de los de los Santos

Several phosphorus-substituted N-acylated cyanoaziridines 2 and N-carbamoylated cyanoziridines 5 were prepared in good to high yields. N-Acylated cyanoaziridines 2 were used, after ring expansion, in an efficient synthesis of oxazoline derivative 3a and in a completely regio-controlled reaction in the presence of NaI. Conversely, N-carbamoyl cyanoaziridines 5 reacted with NaI to obtain a regioisomeric mixture of 2-aminocyanooxazolines 7. Mild acidic conditions can be used for the isomerization of N-thiocarbamoyl cyanoaziridine 6a into a 2-aminocyanothiazoline derivative 8a by using BF3·OEt2 as a Lewis acid. Likewise, a one pot reaction of NH-cyanoaziridines 1 with isocyanates obtained 2-iminocyanooxazolidines 9 regioselectively. This synthetic methodology involves the addition of isocyanates to starting cyanoaziridines to obtain N-carbamoyl cyanoaziridines 5, which after the ring opening, reacts with a second equivalent of isocyanate to give the final 2-imino cyanooxazolidines 9. In addition, the cytotoxic effect on the cell lines derived from human lung adenocarcinoma (A549) was also screened. 2-Iminooxazolidines 9 exhibited moderate activity against the A549 cell line in vitro. Furthermore, a selectivity towards cancer cells (A549) over non-malignant cells (MCR-5) was detected.


2011 ◽  
Vol 7 ◽  
pp. 243-245 ◽  
Author(s):  
Benedikt Sammet ◽  
Mathilde Brax ◽  
Norbert Sewald

A novel highly enantioselective two step access to a unit B precursor of cryptophycins in good yields from commercially available starting materials has been developed. The key step is an asymmetric hydrogenation using the commercially available [(COD)Rh-(R,R)-Et-DuPhos]BF4 catalyst. The synthetic route provides the advantage of less synthetic steps, proceeds with high yields and enantioselectivity, and avoids hazardous reaction conditions.


Synlett ◽  
2020 ◽  
Author(s):  
Chuan Wang ◽  
Zhiyang Lin ◽  
Yun Lan

We report a reductive allylic defluorinative reaction of α-trifluoromethyl alkenes with terminal epoxides, which consists of an iodide-mediated regioselective ring opening and a nickel-catalyzed radical-type cross-coupling, providing diverse tertiary gem-difluorobishomoallylic alcohols in moderate to high yields. Notably, this reaction is conducted under mild conditions and requires no external ligand or proton donor.


2012 ◽  
Vol 8 ◽  
pp. 650-657 ◽  
Author(s):  
Xiufang Ji ◽  
Zhiming Li ◽  
Quanrui Wang ◽  
Andreas Goeke

The fused 2-vinyl or 2-phenyl substituted cyclobutanones 4 undergo stereoselective ring openings by the action of alkoxide ions (t-BuO− or MeO−) to produce novel vicinally disubstituted cycloalkene derivatives 5 and 6 in moderate to high yields. The ring cleavage usually occurs with complete regioselectivity. The accessibility of γ,δ-unsaturated ester or acid derivatives makes this transformation a good supplementary method for the well-established Johnson–Claisen rearrangement.


2008 ◽  
Vol 86 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Mona Hosseini-Sarvari

MgO catalyzed efficiently the ring opening of epoxides with a range of aromatic and aliphatic amines to produce β-substituted alcohols in high yields under solvent-free conditions. Exclusive trans stereoselectivity is observed for cyclic epoxide.Key words: MgO, β-amino alcohols, solvent-free, epoxide, amine.


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