刚性连接子通过引入环（脂肪环、脂肪杂环、芳香环等）来替代线性连接子，可以有效减少药物分子中可旋转键数量，限制化合物构象，从而有利于提高药物分子对靶点的结合稳定性；另一方面，刚性环相比线性分子更容易调节药物分子的物理化学性质，改善其DMPK，目前在蛋白降解剂类药物中得到广泛应用。
2-(4-(4-Aminophenyl)piperazin-1-yl)ethanol
Methyl 4-(2-hydroxyethyl)benzoate
tert-Butyl 4-(4-aminophenoxy)piperidine-1-carboxylate
1,2-Bis(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenoxy)ethane
1-Cbz-4-(aminomethyl)piperidine
3-(Methoxycarbonyl)bicyclo[1.1.1]pentane-1-carboxylic acid
2-(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)acetic acid
1-(2-N-Boc-Aminoethyl)piperazine
(4-(((tert-Butoxycarbonyl)amino)methyl)phenyl)boronic acid
Methyl 4-(hydroxymethyl)bicyclo[2.2.2]octane-1-carboxylate
tert-Butyl 6-formyl-2-azaspiro[3.3]heptane-2-carboxylate
tert-Butyl ((3-oxocyclobutyl)methyl)carbamate
tert-Butyl ((4-fluoropiperidin-4-yl)methyl)carbamate
cis-3-(Aminomethyl)cyclobutanol hydrochloride
2-(Piperidin-4-yl)ethanol
3-(Piperazin-1-yl)propan-1-ol
Methyl 3-aminobicyclo[1.1.1]pentane-1-carboxylate
1-(4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzyl)piperazine
4-(4-(2-Hydroxyethyl)piperazin-1-yl)butane-1-sulfonic acid
N-(2-Aminoethyl)-4-piperidinol
tert-Butyl 4-(2-(methylamino)ethyl)piperidine-1-carboxylate
trans-3-Aminocyclobutanecarboxylic acid
cis-3-Aminocyclobutanecarboxylic acid
4-(1-(tert-Butoxycarbonyl)piperidin-4-yl)benzoic acid
tert-Butyl 2-azaspiro[4.5]decan-8-ylcarbamate
Methyl 2-(3-(hydroxymethyl)cyclobutyl)acetate
2-(Piperidin-4yl)acetic acid hydrochloride
1-Boc-3-((Methylamino)methyl)azetidine
tert-Butyl 7-azaspiro[3.5]nonan-2-ylcarbamate
tert-Butyl 6-amino-2-azaspiro[3.3]heptane-2-carboxylate
