Sterol-based cationic lipids with aromatic head groups

A cationic lipid having a structure according to Formula (I):

• or a pharmaceutically acceptable salt thereof,
• wherein {circle around (A)} is selected from optionally substituted arylene or optionally substituted heteroarylene;
• wherein L2 is selected from a bond, optionally substituted (C1-C6) alkylene or optionally substituted (C2-C6) alkenylene;
• wherein X1 is selected from 0;
• wherein R1 is
• wherein a is selected from 0, 1, 2, 3, 4 or 5;
• wherein R2 and R3 are each independently selected from H or optionally substituted (C1-C6)alkyl;
• wherein R4 and R5 are each independently selected from H, or optionally substituted (C1-C6)alkyl;
• wherein L1 is selected from D or E-L3-C(═O)O— wherein the right hand side of the recited structure is bound to the {circle around (A)};
• wherein D is selected from —(C1-C3)alkyl-O—, —OC(═O)O—, —SC(═O)O—, —OC(═O)S—, —(C1-C3)alkyl-OC(═O)O—, or —C(═O)O—, wherein the right hand side of each recited structure is bound to the {circle around (A)};
• wherein E is selected from —O—, or —OC(═O)—, wherein the right hand side of each recited structure is bound to the L3;
• wherein L3 is selected from optionally substituted (C1-C6)alkylene, or optionally substituted (C2-C6)alkenylene;
• and
• Ⓢ is a naturally occurring or non-naturally occurring sterol.