Method for preparing methylated amines of formula: wherein - R 1 and R 2, represent, independently from one another, a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a heterocycle, a silyl group, a siloxy, group, an amino group, an aldimine of formula -N=CHR 6, a ketimine of formula -N=CR 6 R 7, said alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocycle, silyl, siloxy and amine groups being optionally substituted, or - R 1 and R 2, taken together with the nitrogen atom to which they are bonded form a heterocycle that is optionally substituted, or - R 1 and R 2, form with the nitrogen atom to which they are bonded, a carbon-nitrogen double bond (N=C) in order to lead to an aldimine of formula -N=CHR 6 or to a ketimine of formula _N=CR 6 R 7, and - R 6 and R 7, representing, independently from one another, a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a heterocycle, a silyl group, a siloxy group, an amino group, said alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocycle, silyl, siloxy and amino groups being optionally substituted, - R 1, R 2, R 6 and R 7 comprise optionally, an H, C, N, O, F, Si and/or S such as defined hereinbelow; - H represents a hydrogen atom ( 1 H), deuterium ( 2 H) or tritium ( 3 H); - C represents a carbon atom ( 12 C), an isotope 11 C, 13 C or 14 C; - N represents a nitrogen atom ( 14 N), an isotope 15 N; - O represents a nitrogen atom ( 16 O), an isotope 18 O; - F represents a nitrogen atom ( 19 F), an isotope 18 F; - Si represents a silicon atom ( 28 Si), an isotope 29 Si or 30 Si; - S represents a sulphur atom ( 32 S), an isotope 33 S, 34 S or 36 S; characterised in that an amine of formula wherein R 1 and R 2 and N are such as defined hereinabove is reacted, with CO 2 wherein C and O are such as defined hereinabove; in the presence of a catalyst and a silane compound of formula wherein - H is such as defined hereinabove, - R 3, R 4 and R 5 represent, independently from one another, a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a silyl group, a siloxy group, an aryl group, an amino group, said alkyl, alkenyl, alkynyl, alkoxy, silyl, siloxy, aryl and amino groups being optionally substituted, or - R 5 is such as defined hereinabove and R 3 and R 4, taken together with the silicon atom to which they are bonded form a silyl heterocycle that is optionally substituted. - R 1 and R 2, represent, independently from one another, a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a heterocycle, a silyl group, a siloxy, group, an amino group, an aldimine of formula -N=CHR 6, a ketimine of formula -N=CR 6 R 7, said alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocycle, silyl, siloxy and amine groups being optionally substituted, or - R 1 and R 2, taken together with the nitrogen atom to which they are bonded form a heterocycle that is optionally substituted, or - R 1 and R 2, form with the nitrogen atom to which they are bonded, a carbon-nitrogen double bond (N=C) in order to lead to an aldimine of formula -N=CHR 6 or to a ketimine of formula _N=CR 6 R 7, - R 6 and R 7, representing, independently from one another, a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, a heterocycle, a silyl group, a siloxy group, an amino group, said alkyl, alkenyl, alkynyl, aryl, heteroaryl, heterocycle, silyl, siloxy and amino groups being optionally substituted, - R 1, R 2, R 6 and R 7 comprise optionally, an H, C, N, O, F, Si and/or S such as defined hereinbelow; - H represents a hydrogen atom ( 1 H), deuterium ( 2 H) or tritium ( 3 H); - C represents a carbon atom ( 12 C), an isotope 11 C, 13 C or 14 C; - N represents a nitrogen atom ( 14 N), an isotope 15 N; - O represents a nitrogen atom ( 16 O), an isotope 18 O; - F represents a nitrogen atom ( 19 F), an isotope 18 F; - Si represents a silicon atom ( 28 Si), an isotope 29 Si or 30 Si; - S represents a sulphur atom ( 32 S), an isotope 33 S, 34 S or 36 S; - H is such as defined hereinabove, - R 3, R 4 and R 5 represent, independently from one another, a hydrogen atom, a halogen atom, a hydroxyl group, an alkyl group, an alkenyl group, an alkynyl group, an alkoxy group, a silyl group, a siloxy group, an aryl group, an amino group, said alkyl, alkenyl, alkynyl, alkoxy, silyl, siloxy, aryl and amino groups being optionally substituted, or - R 5 is such as defined hereinabove and R 3 and R 4, taken together with the silicon atom to which they are bonded form a silyl heterocycle that is optionally substituted.