Promoted Cycloaddition Reaction Research Articles

Iodine promoted annulation reaction for selective construction of Spiro[indene-2,1′-pyrido[4,3-b]indole] and Benzo[5,6]pyrrolo[3′,2': 3,4]cyclohepta[1,2-b]indole

I2 promoted cycloaddition reaction of 2-hydroxy-2-(indol-3-yl)-indane-1,3-diones with the in situ generated β-enamino esters, which were generated from the reaction of arylamines and dialkyl but-2-ynedioates, showed very interesting molecular diversity. In the presence of 30 % mmol iodine, the reaction in acetonitrile at 80 °C resulted in the novel spiro [indene-2,1′-pyrido [4,3-b]indole] derivatives in good yields. On the other hand, in the presence of 80 % mmol iodine, the reaction in acetonitrile at 60 °C gave the ring-expanded benzo [5,6]pyrrolo [3′,2':3,4]cyclohepta [1,2-b]indole derivatives in moderate to good yields. Additionally, the similar iodine-promoted reaction of 2-(indol-2-yl)diarylmethanols and β-enamino esters gave the unique 1,1,2-triphenyl-2,9-dihydropyrido [3,4-b]indoles in satisfactory yields. A plausible domino annulation mechanism was rationally proposed for the formation of various polycyclic compounds.

Computational investigation of cycloadditions between cyclopentadiene and tropone-3,4-dimethylester.

Thermally promoted cycloaddition reactions of tropone-3,4-dimethylester and cyclopentadiene have been investigated using density functional theory calculations at the M06-2X level and the CBS-QB3 method. The reaction shares several characteristics with previously investigated cycloadditions involving unsubstituted tropone and cyclopentadiene, however substitution of the tropone component with methyl esters results in lower transition state free energy barriers, greater thermodynamic driving forces, and a significant increase in the number of possible pericyclic reaction pathways. Eighteen different [4 + 2], [6 + 4], or [8 + 2] cycloaddition products are possible and many of the initially formed cycloadducts can be interconverted through Cope or Claisen rearrangements. Of the many possible cycloaddition products only two are predicted to form: the exo-[6 + 4] product and one [4 + 2] product where the substituted tropone appears to be the diene. The two computationally predicted products are the same as the two that are observed experimentally, however computations indicate that both products result from ambimodal processes rather than single-step (monomodal) cycloaddition pathways.

Selective synthesis of multifunctionalized cyclopent-3-ene-1-carboxamides and 2-oxabicyclo[2.2.1]heptane derivatives

Triethylamine promoted cycloaddition reaction of phenacylmalononitrile with o-hydroxychalcones or chalcone o-enolates to selectively give cyclopent-3-ene-1-carboxamides and 2-oxabicyclo[2.2.1]heptanes.

Cycloadditions of Donor–Acceptor Cyclopropanes and Nitriles

Lewis acid promoted cycloaddition reactions of donor–acceptor (DA) cyclopropanes are one of the well‐studied approaches for the construction of heterocyclic and carbocyclic frameworks. During our efforts to exploit this strategy for the synthesis and functionalization of carbohydrate‐derived systems, we discovered the cycloaddition of nitriles with DA cyclopropanes. This personal account details our contributions to the development of this cycloaddition. The reaction discovery, methods development, and application in total synthesis along with related examples from others are discussed herein.

ChemInform Abstract: Potassium tert‐Butoxide Promoted Cycloaddition Reaction for the Synthesis of 1,5‐Disubstituted 1,2,3‐Triazoles from Aromatic Azides and Trimethylsilyl‐Protected Alkynes.

AbstractOptimized conditions are developed for the desilylation of the starting alkynes and subsequent cycloaddition with aromatic azides to produce triazoles regioselectively.

Potassium tert-Butoxide Promoted Cycloaddition Reaction for the Synthesis of 1,5-Disubstituted 1,2,3-Triazoles from Aromatic Azides and Trimethylsilyl-Protected Alkynes

The cycloaddition reaction of aromatic azides and trimethylsilyl alkynes upon treatment with desilylating reagents was investigated. In the process, the use of <i>t</i>-BuOK in wet DMF generated 1,5-disubstituted 1,2,3-triazoles regioselectively in moderate to good yields at ambient temperature.

ChemInform Abstract: AgSbF6‐Promoted Cycloaddition Reaction of 2‐Trifluoromethyl‐N‐tosylaziridine with Aldehydes.

AbstractThe title reaction affords cis‐4‐trifluoromethyl‐2‐substituted‐1,3‐oxazolidines (III) with high regio‐ and stereoselectivity.

AgSbF6-Promoted Cycloaddition Reaction of 2-Trifluoromethyl-N-tosylaziridine with Aldehydes

2-Trifluoromethyl-N-tosylaziridine reacted with various aldehydes in the presence of a catalytic amount of AgSbF(6) to provide the corresponding cis-4-trifluoromethyl-2-substituted-N-tosyl-1,3-oxazolidines with excellent regio- and stereoselectivity.

ChemInform Abstract: PEG‐400 as Green Reaction Medium for Lewis Acid Promoted Cycloaddition Reactions with Isoeugenol and Anethole.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

A Concise Access to 6-Azabicyclo[3.1.0]hexanes via High-Pressure Promoted Cycloaddition Reaction of Azides to ABH

A Concise Access to 6-Azabicyclo[3.1.0]hexanes via High-Pressure Promoted Cycloaddition Reaction of Azides to ABH

High pressure promoted tandem [4+2]/[3+2] cycloadditions on the solid phase

High pressure was applied to perform tandem [4+2]/[3+2] cycloadditions of enol ethers with nitrostyrenes and resin-bound acrylate. The scope of this tandem cycloaddition was studied by using building blocks with an increasing substitution pattern, resulting in the formation of highly substituted nitroso-acetals. To date, this is the first reported high pressure promoted cycloaddition reaction on a solid support.

Copper(I)-promoted cycloaddition reactions of pyridine-2-carbonitrile, 2-pyridylacetonitrile and isoquinoline-3-carbonitrile with ketones

The copper-promoted cycloaddition between nitrogen heterocyclic compounds (pyridine-2-carbonitrile, 2-pyridylacetonitrile and isoquinoline-3-carbonitrile) and ketones (acetone, pentan-2-one and pentan-3-one) has been studied, and a mechanism proposed on the basis of single crystal X-ray analysis, and 1H NMR and IR spectra of intermediate products.