Use of silicon compounds to dye human keratin fibers; novel compounds and compositions containing them

A compound of formula (3) or a salt thereof:

• wherein:
• R1, R2, and R3 are independently selected from linear or branched, saturated or unsaturated, C1-C8 alkyl and alkenyl radicals,
• each A denotes a radical independently selected from formula (4a), (4b), (4c) and (4d) below:
• wherein:
• each R4 independently represents a linear or branched C1-C6 alkyl radical, OH, C1-C4 alkoxy, hydroxy(C1-C4)alkyl, COOH, CONH2, CN, SO3H, a halogen, an NO2 radical, or a radical NR5R6 wherein
• R5 and R6 independently denote a hydrogen atom, a C1-C8 alkyl or hydroxy(C1-C4)alkyl or amino(C1-C4)alkyl radical, or form, together with the nitrogen atom to which they are attached, a 5- or 6-membered heterocycle which is interrupted by an oxygen or sulphur atom;
• m is an integer ranging from 0 to 2;
• n is an integer equal to 1 or 2;
• D is an —SO2NH—, —CONH— or —O— radical or a radical —NR7— wherein R7 is H or CH3;
• and
• W is a divalent radical of formula (5):
• or of formula (6):
• —HC═CH—(Z)p— (6)
• wherein:
• R8 denotes a hydrogen atom, a hydroxyl radical or a linear or branched, saturated or unsaturated, C1-C8 alkyl radical,
• Z is a linear or branched C1-C6 alkylene radical optionally substituted with an OH radical or a linear or branched, saturated or unsaturated, C2-C8 alkoxy radical, and
• p is an integer equal to 0 or 1, with the proviso that in formula (3), when
• (i) A is a group of formula (4d), and R8 is H, and R1, R2 and R3 all are C1-C8 alkyl groups, then D is other than the group NR7;
• and
• (ii) R1, R2, and R3 are simultaneously methyl, and A is a group of formula (4a) wherein D is a —CONH— radical, then W is a radical of formula (5) other than wherein R8 is H, Z is methylene, and p is equal to 1.

A process for the dyeing of human keratin fibres, comprising the step of applying to said fibres a dye composition, comprising at least one compound of formula (3) or a salt thereof in a medium which is suitable for dyeing:

• wherein:
• R1, R2, and R3 are the same or different from each other selected from linear or branched, saturated or unsaturated, C1-C8 alkyl and alkenyl radicals,
• each A denotes a radical independently selected from formula (4a), (4b), (4c) and (4d) below:
• wherein:
• each R4 independently represents a linear or branched C1-C6 alkyl radical, OH, C1-C4 alkoxy, hydroxy(C1-C4)alkyl, COOH, CONH2, CN, SO3H, a halogen, an NO2 radical, or a radical NR5R6 wherein
• R5 and R6 independently denote a hydrogen atom, a C1-C8 alkyl or hydroxy(C1-C4)alkyl or amino(C1-C4)alkyl radical, or form, together with the nitrogen atom to which they are attached, a 5- or 6-membered heterocycle which is interrupted by an oxygen or sulphur atom;
• m is an integer ranging from 0 to 2;
• n is an integer equal to 1 or 2;
• D is an —SO2NH—, —CONH— or —O— radical or a radical —NR7— wherein R7 is H or CH3;
• and
• W is a divalent radical of formula (5):
• or of formula (6):
• —HC═CH—(Z)p— (6)
• wherein:
• R8 denotes a hydrogen atom, a hydroxyl radical or a linear or branched, saturated or unsaturated, C1-C8 alkyl radical,
• Z is a linear or branched C1-C6 alkylene radical optionally substituted with an OH radical or a linear or branched, saturated or unsaturated C2-C8 alkoxy radical, and
• p is an integer equal to 0 or 1, with the proviso that in formula (3), when
• (i) A is a group of formula (4d), and R8 is H, and R1, R2 and R3 all are C1-C8 alkyl groups, then D is other than the group NR7;
• and
• (ii) R1, R2, and R3 are simultaneously methyl, and A is a group of formula (4a) wherein D is a —CONH— radical, then W is a radical of formula (5) other than wherein R8 is H, Z is methylene, and p is equal to 1.