A protecting group for solution-phase peptide synthesis, the protecting group having a chemical formula selected from the group consisting of Chemical Formula 1, Chemical Formula 2, Chemical Formula 3, Chemical Formula 4, Chemical Formula 5, Chemical Formula 6, Chemical Formula 7, and Chemical Formula 8; wherein Chemical Formula 1 is: wherein Chemical Formula 2 is: wherein Chemical Formula 3 is: wherein Chemical Formula 4 is: wherein Chemical Formula 5 is: wherein Chemical Formula 6 is: wherein Chemical Formula 7 is: wherein Chemical Formula 8 is: wherein: Z is selected from the group consisting of: -H, a methyl group (-Me), and a methoxy group (-OMe); Y is selected from the group consisting of: -O-, -S-, and -NH-; X is selected from the group consisting of: -O-, -S-, and -NH-; R is selected from the group consisting ofH, methyl, -CH 2 SH, -CH 2 CH 2 COOH, - CH 2 COOH, benzyl, 4-(1H-imidazolyl)methyl, -CH(CH 3)(CH 2 CH 3), - CH 2 CH 2 CH 2 CH 2 NH 2, -CH 2 CH 2 CH 2 NH 2, isobutyl, -CH 2 CH 2 SCH 3, -CH 2 CONH 2, - CH 2 CH 2 CONH 2, a propyl group wherein the 1-position of the propyl group is attached to the same position as the R group and the 3-position of the propyl group is attached to the nitrogen, -CH 2 CH 2 CH 2 N=C(NH 2) 2, -CH 2 OH, 1-hydroxyethyl, isopropyl, 4-hydroxybenzyl, and 3-(1H-indolyl)methyl; and L is selected from the group consisting of: 4-(hydroxymethyl)phenoxyacetyl ("HMPA"), 4-(hydroxymethyl)phenoxybutanoyl ("HMPB"), 4-(hydroxymethyl)benzoyl ("HMB"), 4-(mercaptomethyl)benzoyl ("MMB"), 4-(mercaptomethyl)phenoxyacetyl ("MMPA"), 4-(aminomethyl)phenoxyacetyl ("AMPA"), 4-(3,3-dimethyl-3-hydroxypropyl)phenoxyacetyl ("DMPPA"), 2-(4-(amino(2,4-dimethoxyphenyl)methyl)phenoxy)acetyl ("Rink Amide"), 4-((9-amino-9H-xanthen-3-yl)oxy)butanoyl ("Xanthenyl"), 5-(5-amino-10,11-dihydro-5H-dibenzo[a,d] annulen-3-yl)pentanoyl ("TCA"), and 3-(4-(chloro(2-chlorophenyl)(phenyl)methyl)phenyl)propanoyl ("2-Chlorotrityl"). wherein Chemical Formula 1 is: wherein Chemical Formula 2 is: wherein Chemical Formula 3 is: wherein Chemical Formula 4 is: wherein Chemical Formula 5 is: wherein Chemical Formula 6 is: wherein Chemical Formula 7 is: wherein Chemical Formula 8 is: wherein: Z is selected from the group consisting of: -H, a methyl group (-Me), and a methoxy group (-OMe); Y is selected from the group consisting of: -O-, -S-, and -NH-; X is selected from the group consisting of: -O-, -S-, and -NH-; R is selected from the group consisting ofH, methyl, -CH 2 SH, -CH 2 CH 2 COOH, - CH 2 COOH, benzyl, 4-(1H-imidazolyl)methyl, -CH(CH 3)(CH 2 CH 3), - CH 2 CH 2 CH 2 CH 2 NH 2, -CH 2 CH 2 CH 2 NH 2, isobutyl, -CH 2 CH 2 SCH 3, -CH 2 CONH 2, - CH 2 CH 2 CONH 2, a propyl group wherein the 1-position of the propyl group is attached to the same position as the R group and the 3-position of the propyl group is attached to the nitrogen, -CH 2 CH 2 CH 2 N=C(NH 2) 2, -CH 2 OH, 1-hydroxyethyl, isopropyl, 4-hydroxybenzyl, and 3-(1H-indolyl)methyl; and L is selected from the group consisting of: 4-(hydroxymethyl)phenoxyacetyl ("HMPA"), 4-(hydroxymethyl)phenoxybutanoyl ("HMPB"), 4-(hydroxymethyl)benzoyl ("HMB"), 4-(mercaptomethyl)benzoyl ("MMB"), 4-(mercaptomethyl)phenoxyacetyl ("MMPA"), 4-(aminomethyl)phenoxyacetyl ("AMPA"), 4-(3,3-dimethyl-3-hydroxypropyl)phenoxyacetyl ("DMPPA"), 2-(4-(amino(2,4-dimethoxyphenyl)methyl)phenoxy)acetyl ("Rink Amide"), 4-((9-amino-9H-xanthen-3-yl)oxy)butanoyl ("Xanthenyl"), 5-(5-amino-10,11-dihydro-5H-dibenzo[a,d] annulen-3-yl)pentanoyl ("TCA"), and 3-(4-(chloro(2-chlorophenyl)(phenyl)methyl)phenyl)propanoyl ("2-Chlorotrityl"). Z is selected from the group consisting of: -H, a methyl group (-Me), and a methoxy group (-OMe); Y is selected from the group consisting of: -O-, -S-, and -NH-; X is selected from the group consisting of: -O-, -S-, and -NH-; R is selected from the group consisting ofH, methyl, -CH 2 SH, -CH 2 CH 2 COOH, - CH 2 COOH, benzyl, 4-(1H-imidazolyl)methyl, -CH(CH 3)(CH 2 CH 3), - CH 2 CH 2 CH 2 CH 2 NH 2, -CH 2 CH 2 CH 2 NH 2, isobutyl, -CH 2 CH 2 SCH 3, -CH 2 CONH 2, - CH 2 CH 2 CONH 2, a propyl group wherein the 1-position of the propyl group is attached to the same position as the R group and the 3-position of the propyl group is attached to the nitrogen, -CH 2 CH 2 CH 2 N=C(NH 2) 2, -CH 2 OH, 1-hydroxyethyl, isopropyl, 4-hydroxybenzyl, and 3-(1H-indolyl)methyl; and L is selected from the group consisting of: 4-(hydroxymethyl)phenoxyacetyl ("HMPA"), 4-(hydroxymethyl)phenoxybutanoyl ("HMPB"), 4-(hydroxymethyl)benzoyl ("HMB"), 4-(mercaptomethyl)benzoyl ("MMB"), 4-(mercaptomethyl)phenoxyacetyl ("MMPA"), 4-(aminomethyl)phenoxyacetyl ("AMPA"), 4-(3,3-dimethyl-3-hydroxypropyl)phenoxyacetyl ("DMPPA"), 2-(4-(amino(2,4-dimethoxyphenyl)methyl)phenoxy)acetyl ("Rink Amide"), 4-((9-amino-9H-xanthen-3-yl)oxy)butanoyl ("Xanthenyl"), 5-(5-amino-10,11-dihydro-5H-dibenzo[a,d] annulen-3-yl)pentanoyl ("TCA"), and 3-(4-(chloro(2-chlorophenyl)(phenyl)methyl)phenyl)propanoyl ("2-Chlorotrityl").