Abstract: Methylsilacyclopentenyl-containing amides and lactams, such as methylsilacyclopentenyl-N-methylacetamide and methylsilacyclopentenyl-epsilon-caprolactam are disclosed. These compounds display unexpected silylating ability when mixed with an active-hydrogen-containing compound. In particular, organic and organosilicon compounds having at least one --OH, --SH, ##STR1## or --NH.sub.2 group are readily converted to a methylsilacyclopentenyl derivative.

Abstract: Mixing methylvinyldi-(epsilon-caprolactamo)silane with an organosiloxane having silicon-bonded hydroxyl radicals increases the molecular weight by chain extension. This method is particularly useful in making high molecular weight polydiorganosiloxanes containing vinyl radicals from hydroxyl endblocked polydiorganosiloxane fluids.

Abstract: A one package low modulus room temperature vulcanizable silicone elastomer composition is obtained by mixing 100 parts by weight of a hydroxyl endblocked polydimethylsiloxane, 0 to 200 parts by weight of a non-acidic, non-reinforcing filler, 2.5 to 10 parts by weight of ##STR1## in which R is methyl or phenyl, 1 to 6 parts by weight of an aminoxysilicon compound having 3 to 10 aminoxy groups per molecule, and 1 to 5 parts by weight of N,N-dimethyl-formamide, acetonitrile, or N-n-butylacetamide. The low modulus silicone elastomer is useful in building construction. The composition has improved slump characteristics at low temperatures.