Organosilicon compounds VI. The preparation of silylaziridines and silyldiaziridines by silicon-carbon cleavage

The preparation of several 2-furyl-, 2-thienyl-, benzyl-, and allylsubstituted silanes is reported. Such derivatives, when treated with aziridine in the presence of a metal catalyst, afford good yields of silylaziridines and silyldiaziridines. A qualitative study of electronic and steric requirements of the displacement reaction is reported.     

Organosilicon compounds XIII. Cleavage of the silicon-carbon bond of 2-trimethylsilylbenzothiazole

The high-yield synthesis of 2-trimcthylsilylbenzothiazole is described, and the labile nature of this silicon-helerocyclic bond is proved when cleavage is affected by aldehydes, acid halides, chloro-formates and anhydrides. Justification for this unusual reactivity and further insight into the reaction mechanism is offered.     

Organosilicon compounds : XIV. The cleavage of 2-(trimethylsilyl)- and 2-(trimethylstannyl)-1-methylpyrrole and -thiophene with some carbonyl-containing reagents

Cleavage of the metal-carbon bond of 2-(trimethylsilyl)- and 2-(trimethylstannyl)-1-methylpyrrole and -thiophene with several carbonyl-containing reagents has been effected and substantiates our previous tenet for the importance of bond polarity on reactivity     

Organosilicon compounds I. A novel synthesis of organosilicon substituted furfurals

The use of the diethylacetal moiety of 2-furfuraldiethylacetal as a carbonyl blocking agent during n-butyllithium metalations is described. The synthesis of 5-silicon substituted furfurals is accomplished for the first time with NMR data being employed as a means of structure proof. Furthermore, the isolation of the uniquely stable organo-lithium salt, 5-lithio-2-furfuraldiethylacetal, is reported.     

Organosilicon compounds III. Silicon-substituted thiophene derivatives of mercaptoethylamine as possible radioprotective agents

The preparation of the first organosilicon containing derivatives of mercaptoethylamine as possible radioprotective agents is described. The synthesis of these compounds via the thiazolidine intermediate was chosen due to the known radioprotective action of certain thiazolidines. We have prepared seventeen previously unreported organosilicon derivatives of which eleven contain the thiazolidine moiety and six are derivatives of mercaptoethylamine. The ability of these derivatives to protect against ionizing radiation will be determined.     

Photoelectron Spectra of Azabenzenes and Azanaphthalenes: III. The orbital sequence in methyl- and trimethylsilyl-substituted pyridines

The ionization potentials of methyl-, t-butyl- and trimethylsilyl-substituted pyridines have been determined by high-resolution photoelectron spectroscopy. The results are discussed in terms of destabilizing inductive and stabilizing conjugative effects of the substituents, and have been parametrized on the basis of a HMO-type perturbation treatment. Our data are in accord with the idea that the topmost occupied orbital in pyridine is a ‘lone pair’ orbital.