ChemInform Abstract: The Cyclopropylmethyl Free Radical Clock. Calibration for the Range 30-89 °C.

Five 1-alkyl-3-methylindazoles were prepared by treatment of 1-(2-bromophenyl)-1-methoxy-1-(2-alkylazo)ethanes with tri-n-butyl stannane and AIBN at 80 °C in benzene. Yields in the radical cyclization step ranged from 39 to 92%. 1-Phenyl-3-methylindazole was prepared by an analogous route but in very poor yield (<5%). Rate constants for the 5-endo radical closures [Formula: see text], estimated by the radical clock method, were 5.2 × 109 s−1 and 9.2 × 108 s−1 for two of the alkyl systems. Rate constants for analogous 5-endo cyclizations of aryl radicals onto C—C double bonds are much smaller than those for cyclizations to the azo functional group. Keywords: cyclization, radical; azo group, radical closure to; indazoles, radical synthesis of.

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Further Evidence for the Radical Chain Character of Grignard's Reagent Formation. Use of Free Radical Clock in Conjunction with Changes in Concentration of Active Mg.

Tetrahedron ◽

10.1016/0040-4020(95)00814-o ◽

1995 ◽

Vol 51 (46) ◽

pp. 12601-12610 ◽

Cited By ~ 9

Author(s):

Eric Péralez ◽

Jean-Claude Négrel ◽

Michel Chanon

Keyword(s):

Free Radical ◽

Radical Chain ◽

Chain Character ◽

Radical Clock

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Potentiation of bromotrichloromethane hepatotoxicity in male rats exposed to 10 ppm dietary chlordecone: Electron Microscopic and biochemical study

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100158972 ◽

1990 ◽

Vol 48 (3) ◽

pp. 284-285

Author(s):

O. M. Faroon ◽

R. W. Henry ◽

M. G. Soni ◽

H. M. Mehendale

Keyword(s):

Free Radical ◽

Biochemical Study ◽

Prior Exposure ◽

Male Rats ◽

Cellular Injury ◽

Low Doses ◽

Mixed Function Oxidase ◽

Electron Microscopic ◽

Potent Inducer ◽

Cellular Energy

Previous work has shown that mirex undergoes photolytic dechlorination to chlordecone (CD) (KeponeR) in the environment. Much work has shown that prior exposure to nontoxic levels of CD causes potentiation of hepatotoxicity and lethality of CCl4, BrCCl3 and other halomethane compounds. Potentiation of bromotrichloromethane hepatotoxicity has been associated with compounds that stimulate the activity of hepatic mixed-function oxidase (MFO). An increase in the metabolism of halomethane by the MFO to a free radical initiates peroxidative decomposition of membranal lipids ending in massive cellular injury. However, not all MFO inducers potentiate BrCCl3 hepatotoxicity. Potentiation by much larger doses of phenobarbital is minimal and th at by a more potent inducer of MFO, mirex, is negligible at low doses. We suggest that the CD and bromotrichloromethane interaction results in a depletion of cellular energy and thereby reducing the cellular ability to undergo mitosis.

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Deaminative carbonylative thioesterification of activated alkylamines with thiophenols under transition-metal-free conditions

Organic Chemistry Frontiers ◽

10.1039/d0qo01479f ◽

2021 ◽

Author(s):

Fengqian Zhao ◽

Xiao-Feng Wu

Keyword(s):

Free Radical ◽

Transition Metal ◽

Metal Free

A transition-metal-free radical carbonylation of activated alkylamines with thiophenols has been successfully developed. Various thioesters were selectively produced with moderate to good yields.

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