Amines hawthorn

The idea that hydrogen bonding, as a special ortho effect of the substrate, may be involved in the transition state of the reactions with amines was first proposed by Chapman et al. Attempting to test this hypothesis, Hawthorne investigated the hydrogen-isotope effect in the reaction of o- and p-chloronitrobenzene with... 

The vinylbenzyl chloride (VBC) monomer used in this work was purchased from Aldrich (Milwaukee, WI) as an inhibited monomer mixture of the 3- and 4- isomers. The inhibitor was removed from the monomer by contact with a column of De-hibit 100 Ion Exchange Resin from Polysciences (Warrington, PA). The divinylbenzene used as a crosslinking agent was also purchased from Aldrich as an inhibited 55% solution of the isomers with 3- and 4-ethylvinylbenzene. Due to the extremely small amount of divinylbenzene used in the monomer mixtures, the inhibitor was not removed prior to polymerization. The remaining reactants and solvents include triethyl amine (99%), trimethyl phosphite (99+%), triisopropyl phosphite (95%), acetone, chloroform, and hexyl alcohol which were also purchased from Aldrich. The photoinitiator used to initiate the polymerizations was Irgacure907, donated by CibaGeigy (Hawthorne, NY). 

General procedure A sealable Schlenk tube was charged with Ni(cod)2 (6 mg, 0.02 mmol, 2 mol%), dppf (22 mg, 0.04 mmol, 4 mol%), and sodium tert-butoxide (135 mg, 1.4 mmol) under Ar in a Vacuum Atmospheres Company (Hawthorne, CA) glove box. Toluene (1 mL) was added, followed by the aryl chloride (1.0 mmol), amine (1.2 mmol), and additional toluene (3 mL). The tube was sealed, removed from the... 

John specialized in fluorine, boron, sulfur, phosphorus, and metal carbonyl chemistry. With M. Frederick Hawthorne, he discovered a series of amine complexes of aluminum trihydride and showed that some of them give aluminum metal when heated this process later became useful for the formation of aluminum thin films by chemical vapor deposition. One of his notable achievements was the discovery that the PPN cation, bisftriphenylphosphoranyhdene) ammonium, forms air-stable salts with many air-sensitive anions such as [Co(CO)4] . He also discovered that cesium fluoride can serve as a catalyst for the synthesis of organic fluoroxy compounds (RpOF) by the fluorination of acyl halides. 

E. M. Georgiev, K. Shelly, D. A. Feakes, J. Kuniyoshi, S. Romano, M. Hawthorne, Synthesis of amine derivatives of the polyhedral borane anion [BjoHig] ", Inorg. Chem., 1996, 35, 5412-5416. 

Hawthorne DG, Hodgkin JH (1999) Amine reactivity changes in imide formation from heterocyclic bases. High Perform Polym 11 315-329... 

Four nucleophilic aromatic substitution reactions with amines have been studied for deuterium isotope effects. Hawthorne (81) found that the rates of reaction of o- and p- nitrochlorobenzene with piperidine in xylene are not altered by substitution of deuterium for hydrogen on the amino group of the nucleophile. Similarly, 2,4-dinitrochlorobenzene reacts at identical rates with -butylamine and with iV,iV-dideuterio-n-butylamine containing 0.75% ethanol (76). Under the conditions of the rate measurements the deuterated amine does not undergo exchange with either the chloroform or the ethanol present. Finally, the reaction of trichloro-s-triazene with aniline shows no isotope effect with AT,JV-dideuterioaniline in benzene as well as in benzene saturated with deuterium oxide (82). 

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