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 2,7-diazaspiro[3.5]nonane-2-carboxylate hydrochloride
1'-(tert-Butoxycarbonyl)-[1,3'-biazetidine]-3-carboxylic acid
1-Boc-4-(4-Bromophenoxy)piperidine
Methyl 4-aminobicyclo[2.2.2]octane-1-carboxylate hydrochloride
4-((tert-Butoxycarbonyl)amino)bicyclo[2.2.2]octane-1-carboxylic acid
tert-Butyl 4-(bromomethyl)benzylcarbamate
Methyl 6-((tert-butoxycarbonyl)amino)spiro[3.3]heptane-2-carboxylate
tert-Butyl ((trans-4-(hydroxymethyl)cyclohexyl)methyl)carbamate
tert-Butyl 4-(bromomethyl)piperidine-1-carboxylate
1-Boc-(3-Carboxymethoxy)azetidine
tert-Butyl (4-(aminomethyl)benzyl)(methyl)carbamate
tert-Butyl azetidin-3-ylmethyl(methyl)carbamate
4-(4-Methoxyphenyl)-1-butanol
4-(4-(tert-Butoxycarbonyl)piperazin-1-yl)benzoic acid
tert-Butyl 3-ethynylazetidine-1-carboxylate
tert-Butyl (piperidin-4-ylmethyl)carbamate
tert-Butyl 4-(2-hydroxyethyl)piperazine-1-carboxylate
tert-Butyl ((4-oxocyclohexyl)methyl)carbamate
tert-Butyl 4-(2-aminoethyl)piperazine-1-carboxylate
Methyl 3-(4-aminophenyl)propanoate
trans-4-Aminocyclohexanecarbonitrile hydrochloride
tert-Butyl (4-hydroxybicyclo[2.2.2]octan-1-yl)carbamate
tert-Butyl 4-(3-aminopropyl)piperazine-1-carboxylate
tert-Butyl (6-hydroxyspiro[3.3]heptan-2-yl)carbamate
6-((tert-Butoxycarbonyl)amino)spiro[3.3]heptane-2-carboxylic acid
tert-Butyl (6-oxospiro[3.3]heptan-2-yl)carbamate
Methyl 6-oxospiro[3.3]heptane-2-carboxylate
4-(4-(tert-Butoxycarbonyl)piperazin-1-yl)-4-oxobutanoic acid
tert-Butyl [4,4'-bipiperidine]-1-carboxylate
4-(Piperazin-1-ylmethyl)benzoic acid dihydrochloride
