Sequential multicomponent site-selective synthesis of 4-iodo and 5-iodopyrrole-3-carboxaldehydes from a common set of starting materials by tuning the conditions

2020 ◽  
Vol 18 (6) ◽  
pp. 1155-1164 ◽  
Author(s):  
Sachin Choudhary ◽  
Jyothi Yadav ◽  
Mamta ◽  
Amol Prakash Pawar ◽  
Satheeshvarma Vanaparthi ◽  
...  
Keyword(s):  
Selective Synthesis ◽  
Reaction Conditions ◽  
Straightforward Method ◽  
High Yields ◽  
Site Selective

A simple and straightforward method for the synthesis of 4-iodo and 5-iodopyrrole-3-carboxaldehydes is developed in good to high yields (up to 78%) from a common set of starting materials by tuning the reaction conditions.

scholarly journals H3PW12O40: An Efficient and Recyclable Heterogeneous Catalyst for the Selective Synthesis of 2-Aryl-5,6-dihydro-4H-1,3-oxazines and 2-Aryl-1,4,5,6-tetrahydropyrimidines

2010 ◽  
Vol 65 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Iraj Mohammadpoor-Baltork ◽  
Majid Moghadam ◽  
Shahram Tangestaninejad ◽  
Valiollah Mirkhani ◽  
Zohre Eskandari
Keyword(s):  
Heterogeneous Catalyst ◽  
High Purity ◽  
Environmentally Friendly ◽  
Thermal Conditions ◽  
Selective Synthesis ◽  
Reaction Conditions ◽  
Efficient Procedure ◽  
Mw Irradiation ◽  
High Yields ◽  
Recyclable Heterogeneous Catalyst

An environmentally friendly and highly efficient procedure has been developed for the selective synthesis of 2-aryl-5,6-dihydro-4H-1,3-oxazines and 2-aryl-1,4,5,6-tetrahydropyrimidines by cyclocondensation of arylnitriles with 3-amino-1-propanol and 1,3-diaminopropane in the presence of catalytic amounts of H3PW12O40 under thermal conditions and MW irradiation. Under the same reaction conditions, dicyanobenzenes are transformed to their corresponding mono-oxazines and monotetrahydropyrimidines with excellent chemoselectivity. These reactions are simple and clean, giving the products in high yields and high purity. The catalyst can be easily recovered after the reaction and reused efficiently in subsequent runs.

Selective synthesis of E-isomers of aldoximes via a domino aza-Michael/retro-Michael reaction

2012 ◽  
Vol 66 (4) ◽  
Author(s):  
Wei Chen ◽  
Wei-Guo Yu ◽  
Hai-Bo Shi ◽  
Xiao-Yan Lu
Keyword(s):  
1H Nmr ◽  
Room Temperature ◽  
Stereoselective Synthesis ◽  
Michael Reaction ◽  
Selective Synthesis ◽  
Reaction Conditions ◽  
High Yields ◽  
Diastereomeric Purity ◽  
Benzylidene Malononitrile

AbstractA highly stereoselective synthesis of E-isomer of aldoximes was developed through a base-catalysed domino aza-Michael/retro-Michael reaction of hydroxylamine and 2-(R-benzylidene)malononitrile. This reaction generates (E)-aldoxime diastereomer in high yields (eight examples, isolated yields of 82-93 %), excellent diastereomeric purity (diastereomeric ratio higher than 95: 5 by 1H NMR), and proceeds under mild reaction conditions (aqueous NaOH, pH 12, room temperature, 4 h).

A zinc-catalyzed oxidative reaction of ynamides with phenols and thiophenols: highly site-selective synthesis of versatile α-aryloxy amides and α-arylthio amides

2016 ◽  
Vol 3 (8) ◽  
pp. 989-993 ◽  
Author(s):  
Peng-Peng Ruan ◽  
Cang-Hai Shen ◽  
Long Li ◽  
Chao-Yue Liu ◽  
Long-Wu Ye
Keyword(s):  
Noble Metal ◽  
Selective Synthesis ◽  
Reaction Conditions ◽  
Oxidative Reaction ◽  
Metal Catalyzed ◽  
Site Selective

A zinc-catalyzed oxidative reaction of ynamides with phenols and thiophenols under mild reaction conditions has been developed, which provides various α-aryloxy amides and α-arylthio amides in moderate to good yields, respectively. Importantly, high chemoselectivity is achieved by such a non-noble metal-catalyzed alkyne oxidation.

Novel One-pot Synthesis of Pyranocarbazole Derivatives via an Isocyanide-based Three-component Reaction

2020 ◽  
Vol 17 ◽  
Author(s):  
Visarapu Malathi ◽  
Pedavenkatagari Narayana Reddy ◽  
Pannala Padmaja
Keyword(s):  
Efficient Method ◽  
Atom Economy ◽  
Reaction Conditions ◽  
One Pot ◽  
Catalyst Free ◽  
One Pot Synthesis ◽  
Three Component Reaction ◽  
High Yields

Abstract:: An efficient method has been developed for the synthesis of new pyrano[3,2-c] and pyrano[3,2-a]carbazole de-rivatives via a three component reaction of 4-hydroxycarbazole or 2-hydroxycarbazole, isocyanides, and dialkylacetylenedi-carboxylates. Noteworthy features of this protocol include mild reaction conditions, catalyst-free, high atom-economy and high yields.

An environmentally benign cascade reaction of chromone-3-carboxaldehydes with ethyl 2-(pyridine-2-yl)acetate derivatives for highly site-selective synthesis of quinolizines and quinolizinium salts in water

2020 ◽  
Vol 22 (20) ◽  
pp. 6943-6953 ◽  
Author(s):  
Li Chen ◽  
Rong Huang ◽  
Kun Li ◽  
Xing-Han Yun ◽  
Chang-Long Yang ◽  
...  
Keyword(s):  
Cascade Reaction ◽  
Environmentally Benign ◽  
Selective Synthesis ◽  
Site Selective ◽  
Reaction In Water

A protocol for the synthesis of quinolizines from ethyl 2-(pyridine-2-yl)acetates via an unprecedented cascade reaction in water was constructed.

scholarly journals A two step synthesis of a key unit B precursor of cryptophycins by asymmetric hydrogenation

2011 ◽  
Vol 7 ◽  
pp. 243-245 ◽  
Author(s):  
Benedikt Sammet ◽  
Mathilde Brax ◽  
Norbert Sewald
Keyword(s):  
Asymmetric Hydrogenation ◽  
Synthetic Route ◽  
Reaction Conditions ◽  
High Yields

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.

scholarly journals A Simple and Efficient Synthesis of Highly Substituted Indeno[1,2-b]pyrrole and Acenaphtho[1,2-b]pyrrole Derivatives by Tandem Three-Component Reactions

Molecules ◽  
2018 ◽  
Vol 23 (11) ◽  
pp. 3031 ◽  
Author(s):  
Xiaodong Tang ◽  
Songlei Zhu ◽  
Ying Ma ◽  
Ren Wen ◽  
Lanqi Cen ◽  
...  
Keyword(s):  
Environmentally Benign ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Dicarbonyl Compounds ◽  
Pyrrole Derivatives ◽  
Three Component Reaction ◽  
High Yields ◽  
Operational Simplicity

A green, convenient and tandem procedure for the efficient synthesis of highly substituted indeno[1,2-b]pyrrole and acenaphtho[1,2-b]pyrrole derivatives by domino three-component reaction of tryptamine/benzylamine, 1,3-dicarbonyl compounds and ninhydrin/ acenaphthenequinone is described. The significant features of this procedure were characterized by mild reaction conditions, high yields, operational simplicity and it being environmentally benign.

scholarly journals New opportunities in the stereoselective dearomatization of indoles

2016 ◽  
Vol 88 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Elisabetta Manoni ◽  
Assunta De Nisi ◽  
Marco Bandini
Keyword(s):  
Acid Catalysis ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Reaction Conditions ◽  
Brönsted Acid ◽  
High Yields ◽  
First Time ◽  
Tailored Design ◽  
Bronsted Acid Catalysis

AbstractThe regio- and stereoselective dearomatization of indoles is realized for the first time by combining readily available indolyl precursors and electron-rich allenes, namely allenamides and aryloxyallenes. Inter- as well as intramolecular condensations were realized under gold and Brønsted acid catalysis providing a range of densely functionalized indoline and indolenine cores in high yields and excellent stereochemical outcome. Chemodivergent reaction profiles (Micheal-type addition vs. [2+2]-cycloaddition) were realized by a tailored design of both reaction conditions and functionalization of the reaction partners.

scholarly journals Site-Selective C-C Modification of Proteins at Neutral pH Using Organocatalyst-Mediated Cross Aldol Ligations

2018 ◽  
Author(s):  
Martin A. Fascione ◽  
Richard J. Spears ◽  
Robin L. Brabham ◽  
Darshita Budhadev ◽  
Tessa Keenan ◽  
...  
Keyword(s):  
Small Molecules ◽  
Stable Carbon ◽  
Biological Mechanisms ◽  
Large Excess ◽  
Reaction Conditions ◽  
Chemical Methods ◽  
Neutral Ph ◽  
Chemical Modification Of Proteins ◽  
A Site ◽  
Site Selective

The bioconjugation of proteins with small molecules has proved an invaluable strategy for probing and perturbing dynamic biological mechanisms. The general use of chemical methods for the functionalisation of proteins remains limited however by the frequent requirement for complicated reaction partners to be present in large excess, and harsh reaction conditions which are incompatible with many protein scaffolds. Herein we describe a site-selective organocatalyst-mediated protein aldol ligation (OPAL) that affords stable carbon-carbon linked bioconjugates at neutral pH under biocompatible conditions. OPAL enables rapid chemical modification of proteins within an hour using simple aldehyde probes in minimal excess, and is utilised here in the selective affinity tagging of proteins in cell lysate. Furthermore we demonstrate that the b-hydroxy aldehyde product of the OPAL can be functionalised a second time at neutral pH in a subsequent organocatalyst-mediated oxime ligation. This tandem strategy is showcased in the ‘chemical mimicry’ of a previously inaccessible natural dual post-translationally modified protein integral to the pathogenesis of the neglected tropical disease Leishmaniasis. <br>

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