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N-Silylated Ureas and Thioureas, Silicon Tetrachloride, Bis(dimethylamino)dimethylsilane N,N′-Diorganylureas react with silicon tetrachloride to give the 1,3,5-triaza-2-silacyclo-hexan-4,6-diones 1-4, in case of N,N′-dicyclohexylurea to give dicyclohexylcarbodiimide. By reacting bis(diethylamino)dimethylsilane with N,N′-diorganylureas and thioureas, resp., one obtains 1,3,5-triaza-2,4-disilacyclohexan-6-ones 6, 10, 13-15, 1-oxa-3,5-diaza-6-silacyclohexan-4-ones 5, 9, 1,3,5-triaza-2-silacyclohexan-4,6-diones 7, 11, 1,3-dioxa-5-aza-2,6-trisilacyclohexanes 8,12, 1,3,5-triaza-2,4-disilacyclohexan-6-thiones 16-25 or the organylamino-diethylamino-dimethylsilanes 26-28. The compounds were characterized analytically and spectroscopically.

The reaction of trimethylsilylamidines with 2-chloro-1,3,4,5,6-pentamethylborazine leads to the corresponding amidinoborazines and chlorotrimethylsilane. 1H, 11B, 11F NMR spectra, mass spectra and characteristic IR group frequencies are reported.

The structure of the title compound (a = 1185.4, b = 1197.7, c = 1764.8 pm, β = 73.96°, space group P21/c) has been determined from X-ray diffractometer data. The molecule is structurally analogous to the tetraborate ion [B4O7]2-. The eight-membered ring is folded by 104° about the B - B vector. The boron atoms are more strongly bonded to the bridging oxygen [B-O(B) 139 pm] than to the other atoms [B-O(C) 155 pm, B-N 160 pm, B-Cl 182 pm].

Piperidine-N-oxyboranes and 2,2,6,6-Tetramethylpiperidine-N-oxyboranes have been prepared starting from halogenoboranes by three methods:

Sulfinamidoboranes are prepared by cleavage of the Si-N-bond

The reaction of trimethylsilylsulfonamides with halodiorganylboranes leads to the corresponding sulfonamidoboranes and halotrimethylsilane. Trimethylsilylsulfonamides are prepared by reaction of the corresponding sulfonyl chlorides with primary amines, followed by the addition of chlorotrimethylsilane in the presence of excess triethylamine. 1H, 11B NMR spectra and mass spectra are reported

N,N',N'-Triorganyl-N-trimethylsilylthioureas react with halogeno diorganyl boranes to yield the N,N',N'-organyl-thioureidoboranes 1-7 and isothioureidoboranes 8-15. 10-15 are intramolecularly associated. The compounds are characterized analytically and spectroscopically (NMR: 1H, 13C, HB; MS; IR).

The reaction of anisole with Na/K-alloy and subsequent reaction with dichloro(diisopropyl-amino)borane yields diisopropylamino(diphenoxy)borane (1). In reacting the sodium complex of 1-or 2-m ethoxynaphthalene, respectively, with dichloro(diorganylamino)boranes the ether bond is cleaved. One obtains the methoxy-2-naphthoxy-diorganylam inoboranes (2a -d) besides the di-2-naphthoxy-diorganylam inoboranes (3a-e), the 2-naphthoxy-bis(diorganylamino)boranes (4a-b) and the solvated sodium-2-naphtholate (6). By-products are 1,2-bis[(diisopropylamino)-1- or 2-naphthoxyboryl]ethyne derivatives 5a and 5b, terized analytically and spectroscopically (MS; NMR: 1H, 11B, 13C).

3,5-Dibromo-1,2,4-trithia-3,5-diborolane reacts with alkynes to give ⊿4-2-bromo-1,3,2- dithiaborolenes. As a by-product in the reaction to form ⊿4-2-bromo-4-phenyl-1,3,2-dithiaborolene the ⊿2,5-4-bromo-2,6-diphenyl-l,4-thiaboracyclohexadiene is formed. Vinyltrimethylsilane reacts with 3,5-dimethyl-1,2,4-trithia-3,5-diborolane to yield the 2-methyl-4- trimethylsilyl-1,3,2-dithiaborolane. The bromine atom in these compounds can be substituted by lithium alkyls, by secondary as well as lithiated primary amines or by lithiohexamethyldisilazane. Starting from ⊿4-2-<-butylamino-4-phenyl-1,3,2-dithiaborolene and heterocycles containing boron bromine functions, diborylamines are obtained. Isocyanates and di-i-propylcarbodiimide, respectively, react with 3,5-dimethyl-1,2,4-trithia-3,5-diborolane by formation of 5-methyl-1,4-dithia-2-azacyclopentanethiones(3) or of -pentanones(3). 3,5-Dimethyl-1,2,4-trithia-3,5-diborolane reacts with o-acetylaminophenole to give 3-acetyl-2-methyi-4,5-benzo-l-oxa-3-aza-2-boracyclopentane. 1H, 11B, 13C NMR, mass and IR spectra are reported.