α-Chymotrypsin-Induced Acetalization of Aldehydes and Ketones with Alcohols

Synthesis ◽  
2020 ◽  
Vol 52 (14) ◽  
pp. 2121-2126
Author(s):  
Zhanggao Le ◽  
Zongbo Xie ◽  
Jin Lan ◽  
Guofang Jiang ◽  
Jiangnan Yang ◽  
...  
Keyword(s):  
Catalytic Amount ◽  
First Report ◽  
Mild Conditions ◽  
Aldehydes And Ketones ◽  
Neutral Conditions ◽  
Induced Reaction ◽  
General Method

This is the first report of a simple and general method for acetalization­ of aldehydes via an α-chymotrypsin-induced reaction under mild conditions. A broad range of aromatic and heteroaromatic aldehydes have been acetalized under neutral conditions in good yields using a catalytic amount of chymotrypsin.

Organophotoredox-Catalyzed C–H Alkylation of Imidazoheterocycles with Malonates: Total Synthesis of Zolpidem

Synthesis ◽  
2020 ◽  
Author(s):  
Narendra R. Chaubey ◽  
Anant R. Kapdi ◽  
Biswanath Maity
Keyword(s):  
Total Synthesis ◽  
Room Temperature ◽  
Drug Molecule ◽  
Bond Functionalization ◽  
First Report ◽  
Mild Conditions ◽  
The Past ◽  
Hypnotic Drug ◽  
Free Environment

AbstractOrganophotocatalytic C–H bond functionalization has attracted a lot of attention in the past several years due to the possibility of catalyzing reactions in a metal- and peroxide-free environment. Continuing on these lines, an organophotoredox-catalyzed C–H functionalization of imidazo[1,2-a]pyridines and related heterocycles with bromomalonates under mild conditions is reported, providing excellent yields of the products at room temperature. This is the first report involving malonates as coupling partners leading to the synthesis of a range of functionalized products including total synthesis of zolpidem, a sedative­-hypnotic drug molecule.

scholarly journals Mild and efficient cyanuric chloride catalyzed Pictet–Spengler reaction

2013 ◽  
Vol 9 ◽  
pp. 1235-1242 ◽  
Author(s):  
Ashish Sharma ◽  
Mrityunjay Singh ◽  
Nitya Nand Rai ◽  
Devesh Sawant
Keyword(s):  
Catalytic Amount ◽  
Nitrogen Atmosphere ◽  
Cyanuric Chloride ◽  
Distinct Advantage ◽  
First Report ◽  
Excellent Yield

A practical, mild and efficient protocol for the Pictet–Spengler reaction catalyzed by cyanuric chloride (trichloro-1,3,5-triazine, TCT) is described. The 6-endo cyclization of tryptophan/tryptamine and modified Pictet–Spengler substrates with both electron-withdrawing and electron-donating aldehydes was carried out by using a catalytic amount of TCT (10 mol %) in DMSO under a nitrogen atmosphere. TCT catalyzed the Pictet–Spengler reaction involving electron-donating aldehydes in excellent yield. Thus, it has a distinct advantage over the existing methodologies where electron-donating aldehydes failed to undergo 6-endo cyclization. Our methodology provided broad substrate scope and diversity. This is indeed the first report of the use of TCT as a catalyst for the Pictet–Spengler reaction.

p-Toluenesulfonic Acid Coated Natural Phosphate as an Efficient Catalyst for the Synthesis of 2-Substituted Benzimidazole

2018 ◽  
Vol 42 (12) ◽  
pp. 614-617
Author(s):  
Soumia Belkharchach ◽  
Hanane Elayadi ◽  
Hana Ighachane ◽  
Said Sebti ◽  
Mustapha Ait Ali ◽  
...  
Keyword(s):  
Environmentally Friendly ◽  
Catalytic Amount ◽  
Reusable Catalyst ◽  
Efficient Catalyst ◽  
Natural Phosphate ◽  
Mild Conditions ◽  
Toluenesulfonic Acid ◽  
High Yields

2-Substituted benzimidazoles are selectively synthesised in high yields via the condensation of o-phenylenediamine derivatives with aldehyde derivatives using catalytic amount of p-toluenesulfonic acid coated natural phosphate (NP/PTSA) under mild conditions. The use of NP/PTSA as a reusable catalyst makes this process simple, convenient, and environmentally friendly.

Ir(iii)-Catalyzed [4 + 2] cyclization of azobenzene and diazotized Meldrum's acid for the synthesis of cinnolin-3(2H)-one

2019 ◽  
Vol 17 (9) ◽  
pp. 2554-2563 ◽  
Author(s):  
Gongutri Borah ◽  
Pitambar Patel
Keyword(s):  
Carboxylic Acid ◽  
Meldrum's Acid ◽  
Meldrum’S Acid ◽  
First Report ◽  
Mild Conditions ◽  
Ester Derivative

The first report on Ir(iii)-catalyzed C–H alkylation/cyclization of azobenzene with diazotized Meldrum's acid was developed for the synthesis of cinnoline-3(2H)-one-4-carboxylic acid and its ester derivative under mild conditions.

Synthesis of poly(amide-imide)s by palladium-catalysed polycondensation of aromatic dibromides containing imide structure, aromatic diamines and carbon monoxide

1994 ◽  
Vol 6 (4) ◽  
pp. 395-403 ◽  
Author(s):  
Mitsuru Ueda ◽  
Takayoshi Yokoo
Keyword(s):  
Carbon Monoxide ◽  
Aprotic Solvents ◽  
Aromatic Diamines ◽  
Structural Units ◽  
Excellent Thermal Stability ◽  
Mild Conditions ◽  
Weight Losses ◽  
Strong Acids ◽  
Dipolar Aprotic Solvents ◽  
General Method

A general method for the preparation of aromatic poly(amide-imide)s, which involves the palladium-catalysed polycondensation of aromatic dibromides containing imide structural units, aromatic diamines and carbon monoxide, has been developed. Polymerizations were carried out in N,N-dimethylacetamide (DMAc) in the presence of palladium catalyst, triphenylphosphine and 1,8-diazabicycIo[5,4,0]-7-undecene (DBU), and gave a series of poly(amide-imide)s with inherent viscosities up to 0.66 dl g-1 under mild conditions. The polymers were quite soluble in strong acids, dipolar aprotic solvents and pyridine. Thermogravimetry of the polymers showed excellent thermal stability, indicating that 10% weight losses of the polymers were observed in the range above 460C in air. The glass transition temperatures of the polymers ranged from 240 to 262C. These polymers also showed good tensile strengths and moduli.

A Facile Synthesis of Functionalised 3H-Pyrroles Promoted by Magnesium and a Catalytic Amount of Iodine

2003 ◽  
Vol 2003 (2) ◽  
pp. 84-86 ◽  
Author(s):  
Xiaoliang Xu ◽  
Yongmin Zhang
Keyword(s):  
Catalytic Amount ◽  
Reductive Coupling ◽  
Facile Synthesis ◽  
Aromatic Nitriles ◽  
Mild Conditions

The intermolecular reductive coupling cyclisation of 3,3-diaryl-2-cyanoacrylonitriles or ethyl 3,3-diaryl-2-cyano-acrylates with aromatic nitriles with magnesium and catalytic iodine in THF afforded 3 H-pyrroles in good yields under neutral and mild conditions.

Sign in / Sign up

Export Citation Format

Share Document