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。
tert-Butyl (3-(hydroxymethyl)bicyclo[1.1.1]pentan-1-yl)carbamate
Methyl 3-(aminomethyl)bicyclo[1.1.1]pentane-1-carboxylate hydrochloride
tert-Butyl ((3-formylbicyclo[1.1.1]pentan-1-yl)methyl)carbamate
tert-Butyl 2-oxo-6-azaspiro[3.4]octane-6-carboxylate
2-(4-((tert-Butoxycarbonyl)amino)cyclohexyl)acetic acid
4-((Trimethylsilyl)ethynyl)benzaldehyde
Ethyl 2-(trans-4-aminocyclohexyl)acetate
Methyl 3-aminocyclobutanecarboxylate hydrochloride
cis-Methyl 3-aminocyclobutanecarboxylate hydrochloride
4-(1-Boc-4-piperidyl)-1-butanol
Methyl 4-(piperidin-4-ylmethyl)benzoate hydrochloride
4-(4-Piperidyl)-1-butanol
Methyl (4-cyanophenyl)acetate
tert-Butyl 2,8-diazaspiro[4.5]decane-8-carboxylate hydrochloride
1,4-Phenylenedimethanamine
tert-Butyl 9-hydroxy-3-azaspiro[5.5]undecane-3-carboxylate
1,4-Benzenediethanol
[1,1'-Bi(cyclohexane)]-4,4'-diol
tert-Butyl 4-(((methylsulfonyl)oxy)methyl)piperidine-1-carboxylate
4-(Azetidin-3-yl)piperazin-2-one hydrochloride
trans-4-Hydroxycyclohexanecarboxylic acid
2-(tert-Butoxycarbonyl)-2-azaspiro[3.3]heptane-6-carboxylic acid
2-(4-Cyanophenyl)acetic acid
3,3'-(Piperazine-1,4-diyl)dipropanoic acid
2,2'-(Piperazine-1,4-diyl)diethanol
4-(3-Aminopropyl)aniline
Dimethyl trans-1,4-Cyclohexanedicarboxylate
tert-Butyl 6-hydroxy-2-azaspiro[3.4]octane-2-carboxylate
Cyclohexane-1,4-diyldimethanamine
tert-Butyl 3-(3-hydroxypropyl)azetidine-1-carboxylate
