INDOL-1-YL-CYCLODISILAZANES AND INDOL-(PY RROL-1-YL)-CYCLODISILAZANESAND TRISILAZANES - SYNTHESIS AND RING CONTRACTION

Dichloro(indol-1-yl)silanes react with lithium-tert.-butylamide to mon o- and bis(amino)-(indol-1-yl)silanes 1-3. In addition to this dichlor obis(pyrrol-1-yl)silane and lithium-tert.-butylamide give the bis(amin o)-bis(pyrrol-1-yl)silane 4, however, with tert.-butylamine the mono(a mino)-chlorobis(pyrrol-1-yl)silane 5 is formed. 3 and 5 are two more e xamples for the rare NH-functional chlorosilanes. Depending on the sto ichiometry the methylamino(pyrrol-1-yl)silanes 6 and 7 are formed in t he reaction of dichlorobis(pyrrolyl-1-yl)silane and methylamine. 7 is formed with displacement of the pyrrolyl-substituent by the more basic methylamino-group. 1 and 2 can be dilithiated and added to difluorosi lanes leading to the cyclodisilazanes 8-10. ris(fluorodimethylsilyl)he xamethylcyclotrisilazane is an educt for pyrrol-1-yl- and (indol-1-yl) silylhexamethylcyclotrisilazanes 11-14. It reacts with one equivalent of lithiumpyrrolide or -indolide to 11 and 12 or with two or three equ ivalents of lithiumpyrrolide to 13 and 14. The inodimethylsilyl)-2.4-b is(dimethyl)cyclodisilazane 15 is formed in the reaction of s(fluorodi methylsilyl)octamethylcyclotetrasilazane with lithiumindolide which ca talyzes the ringcontraction. The crystal structure of 14 is reported.