Wolfgang Tronich

Halomethyl-metal compounds : LVI. Trimethyltindihalomethyllithium reagents☆

Abstract The preparation of trimethyltindichloromethyllithium by reaction of bis(trimethyltin)dichloromethane with n-butyllithium, of trimethyltinbromochloromethyllithium by reaction of bis(trimethyltin)bromochloromethane with n-butyllithium and of trimethyltindibromomethyllithium by reaction of trimethyl(tribromomethyl)tin or bis(trimethyltin)dibromomethane with n-butyllithium is described. All of these new lithium reagents are stable in THF-rich media only at low temperatures (−95° or below). Their reactions with trimethylchlorosilane are complicated by the fact that at such low temperatures the product, trimethylsilyl(trimethyltin)dihalomethane, is comparable in reactivity toward the lithium reagent with trimethylchlorosilane. Similar complications occur with other quenching agents such as methyl iodide.

Halomethyl—metal compounds : LXVII. The application of phenyl(trihalomethyl)mercury compounds in the synthesis of highly halogenated oxiranes

Abstract Phenyl(trihalomethyl)mercury compounds react with highly halogenated ketones [(CF3)2CO, CF3COCF2Cl, (CF2Cl)2CO, CF2ClCOCFCl2], aldehydes (n-C3F7CHO, CCl3CHO) and acid chlorides (CF3COCl, CCl3COCl) to add CX2 to the CO bond, giving oxiranes. In the case of hexachloroacetone and n-C3F7OCF(CF3)CF2OCF(CF3)C(O)F, ketones were obtained instead. In the reactions with the acid chlorides, ketones also were formed in addition to the oxiranes. Reaction of PhHgCCl2Br with oxalyl chloride produced the expected oxirane, 2,3,3-trichloro-2,3-epoxypropenoyl chloride, as well as trichloropyruvyl chloride, trichloroacetyl chloride and hexachlorobiacetyl. A reaction of this mercury reagent with benzil gave PhC(O)-CClPh-C(O)(Cl, most likely via rearrangement of the initially formed oxirane.

New reactions of phenyl(trihalomethyl)mercurials. C-perchloroaziridines and their thermally induced rearrangement

Our recent syntheses of perchlorothiirane’ and polyhalooxiranes2 by the addition of phenyl(trihalomethyl)mercury-derived dihalocarbenes to the appropriate C=S and C=O compounds suggested to us that a similar synthesis of the as yet unknown C-perbaloaziridines might be possible via reaction of PhHgCXs reagents with imines of type RN=CX2 (i.e., isonitrile dihalides). We report here concerning the preparation of C-perchloroaziridines (eq. I) and their surprising thermal and hydrolytic stability.