Cationic lipid containing side-chain functional groups and application thereof

A cationic lipid of the general formula (1):

• wherein, N is a nitrogen branching center;
• L1 and L2 are each independently a linking bond or a divalent linking group;
• L3 is a trivalent linking group;
• L3 and R3 form a divalent linking group -L3(R3)— with R3 as the side chain;
• B1 and B2 are each independently a linking bond or a C1-30 alkylene group;
• R1 and R2 are each independently a C2-30 aliphatic hydrocarbon group or a C2-30 residue of aliphatic hydrocarbon derivative containing one or two oxygen atoms;
• R3 is selected from the group consisting of —ORd, —NRdRd, —SRd, —C(═O)Rd, —C(═O)ORd, —OC(═O)Rd, —OC(═O)ORd, and
• wherein, Rd is, at each occurrence, independently a C1-12 alkyl group;
• G1 is a branching group having a valence of k+1;
• j is 0 or 1;
• F1 contains the functional group R01;
• when j is 0, G1 is absent;
• when j is 1, G1 is connected to k F1, and k F1 are each independently of the same or different structures, wherein k is an integer in the range of 2 to 8;
• R4 is selected from the group consisting of a carbocyclyl group, a heterocyclyl group, and R′N(R′)—R″—N(R′)—;
• wherein, a heterocyclyl group is a cyclic group having 1, 2, or more heteroatoms in its ring atoms, the heteroatom being B, O, N, Si, P, or S;
• wherein, R′ is, at each occurrence, independently H or a C1-3 alkyl group;
• R″ is a C2-4 alkylene group;
• the alkylene group, aliphatic hydrocarbon group, residue of aliphatic hydrocarbon derivative, carbocyclyl group, and heterocyclyl group are each independently substituted or unsubstituted;
• or a salt, tautomer, stereoisomer, or solvate thereof.