Siloxane derivatives of amino acids having surface-active properties
The present disclosure provides siloxane derivatives of amino acids that have surface-active properties. The amino acid can be naturally-occurring or synthetic, or they may be obtained via a ring-opening reaction of a lactam, such as caprolactam. The amino acid may be functionalized with a siloxane group to form a compound that is surface-active and has surfactant characteristics. The compounds have low critical micelle concentrations (CMC) as well as the ability to lower the surface tension of a liquid.
1 . A compound of Formula I:
wherein R 1 and R 2 are the same or different, and comprise at least one group selected from the group consisting of C 1 -C 6 alkyl, optionally the C 1 -C 6 alkyl may include one or more of oxygen, nitrogen, or sulfur atoms or groups that include at least one of these atoms, and the alkyl chain may be optionally substituted with one or more substituents selected from the group consisting of hydroxyl, amino, amido, sulfonyl, sulfonate, carbonyl, carboxyl, and carboxylate;
R 3 is selected from the group consisting of alkenyl, alkynyl, ester, alcohol, aryl alkyl, alkoxy alkyl ether, alkyl phosphate, C 3 -C 8 carboxylic acid, C 1 -C 10 alkyl benzoic acid, and a C 1 -C 6 linker attached to a second molecule of Formula I, wherein the second molecule is the same or different;
n is an integer from 1 to 12; and
X is selected from the group consisting of chloride, bromide, and iodide.
2 . The compound of claim 1 , wherein R 3 is selected from the group consisting of C 2 -C 10 alkenyl, C 2 -C 10 alkynyl, C 2 -C 12 ester, C 1 -C 10 hydroxyl, benzyl, C 2 -C 12 alkoxy alkyl ether, alkyl phosphate, C 3 -C 8 carboxylic acid, C 1 -C 10 alkyl benzoic acid, and a three-carbon linker attached to a second molecule of Formula I, wherein the second molecule is the same as the first molecule.
3 . The compound of claim 1 , wherein R 3 is selected from the formulas consisting of:
4 . The compound of claim 1 , wherein R 1 and R 2 are methyl.
5 . The compound of claim 1 , wherein n is 5.
6 . The compound of claim 1 , wherein the compound is N-benzyl-6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-aminium bromide, having the following formula:
7 . The compound of claim 1 , wherein the compound is N-(2-ethoxy-2-oxoethyl)-6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-aminium bromide, having the following formula:
8 . The compound of claim 1 , wherein the compound is N-allyl-6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-aminium iodide, having the following formula:
9 . The compound of claim 1 , wherein the compound is 6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxo-N-(prop-2-yn-1-yl)hexan-1-aminium bromide, having the following formula:
10 . The compound of claim 1 , wherein the compound is 6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N-(2-(2-methoxyethoxy)ethyl)-N,N-dimethyl-6-oxohexan-1-aminium bromide, having the following formula:
11 . The compound of claim 1 , wherein the compound is N-(3-(diethoxyphosphoryl)propyl)-6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-aminium bromide, having the following formula:
12 . The compound of claim 1 , wherein the compound is 6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N-(3-hydroxypropyl)-N,N-dimethyl-6-oxohexan-1-aminium iodide, having the following formula:
13 . The compound of claim 1 , wherein the compound is 6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N-(2-hydroxyethyl)-N,N-dimethyl-6-oxohexan-1-aminium iodide, having the following formula:
14 . The compound of claim 1 , wherein the compound is N-(5-carboxypentyl)-6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-N,N-dimethyl-6-oxohexan-1-aminium bromide, having the following formula:
15 . The compound of claim 1 , wherein the compound is N 1 ,N 3 -bis(6-((3-(1,1,1,5,5,5-hexamethyl-3-((trimethylsilyl)oxy)trisiloxan-3-yl)propyl)amino)-6-oxohexyl)-N 1 ,N 1 ,N 3 ,N 3 -tetramethylpropane-1,3-diaminium dibromide, having the formula:
16 . A method of synthesizing a compound of Formula I
wherein R 1 and R 2 are the same or different, and comprise at least one group selected from the group consisting of C 1 -C 6 alkyl, optionally the C 1 -C 6 alkyl may include one or more of oxygen, nitrogen, or sulfur atoms or groups that include at least one of these atoms, and the alkyl chain may be optionally substituted with one or more substituents selected from the group consisting of hydroxyl, amino, amido, sulfonyl, sulfonate, carbonyl, carboxyl, and carboxylate;
R 3 is selected from the group consisting of alkenyl, alkynyl, ester, alcohol, aryl alkyl, alkoxy alkyl ether, alkyl phosphate, C 3 -C 8 carboxylic acid, C 1 -C 10 alkyl benzoic acid, and a C 1 -C 6 linker attached to a second molecule of Formula I, wherein the second molecule is the same or different;
n is an integer from 1 to 12; and
X is selected from the group consisting of chloride, bromide, and iodide, the method comprising:
a ring opening step to open lactam ring to provide an amino acid having an N-terminus and a C-terminus;
a first alkylation step, to alkylate the N-terminus to provide a tertiary amine;
a coupling step, to react the C-terminus with 3-aminopropyltris(trimethylsiloxy)silane to provide siloxane derivative; and
a second alkylation step, to alkylate the N-terminus to provide a quaternary amine of Formula I.
17 . The method of claim 16 , wherein the lactam is caprolactam.
18 . The method of claim 16 , wherein in the first alkylation step, the tertiary amine is 6-(dimethylamino)hexanoic acid.
19 . The method of claim 16 , wherein in the second alkylation step, the N-terminus is alkylated with an alkylating agent selected from the group consisting of benzyl bromide, ethyl bromoacetate, allyl iodide, propargyl bromide, 1-bromo-2-(2-methoxyethoxy)ethane, bromo phosphonate, 3-iodopropanol, 3-bromopropanol, 2-iodoethanol, 2-bromoethanol, 6-bromohexanoic acid, and 1,3-dibromopropane.