Branched tail lipid compounds and compositions for intracellular delivery of therapeutic agents

A compound of Formula (A) or (B):

• or its N-oxide, or a salt or isomer thereof,
• wherein R′a is R′branched or R′cyclic;
• wherein
• R′branched is:
• R′ cyclic is:
• wherein
• denotes a point of attachment;
• wherein Raα is H, and Raβ, Raγ, and Raδ are each independently selected from the group consisting of H, C2-12 alkyl, and C2-12 alkenyl, wherein at least one of Raβ, Raγ, and Raδ is selected from the group consisting of C2-12 alkyl and C2-12 alkenyl;
• Raα, Raβ, Raγ, and Raδ are each independently selected from the group consisting of H, C2-30 alkyl, and C5-20 alkenyl, wherein at least one of Raα, Raβ, Raγ, and Raδ is selected from the group consisting of C2-30 alkyl and C5-20 alkenyl;
• R2 and R3 are each C1-14 alkyl;
• R4 is selected from the group consisting of —(CH2)OH, —(CH2)3OH, —(CH2)4OH, —(CH2)5OH and
• wherein R10 is N(R)2;
• each R is independently selected from the group consisting of C1-6 alkyl, C2-3 alkenyl, and H;
• and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10;
• each R5 is independently selected from the group consisting of OH, C1-3 alkyl, C2-3 alkenyl, and H;
• each R6 is independently selected from the group consisting of OH, C1-3 alkyl, C2-3 alkenyl, and H;
• R7 is H;
• M and M′ are each independently selected from the group consisting of —C(O)O— and —OC(O)—;
• R′ is a C1-12 alkyl or C2-12 alkenyl;
• Ya is a C3-6 carbocycle;
• R*″a is selected from the group consisting of C1-15 alkyl and C2-15 alkenyl;
• 1 is selected from the group consisting of 1, 2, 3, 4, and 5;
• s is 2 or 3;
• and
• m is selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, and 13.