Organic electroluminescent compound and organic electroluminescent device comprising the same

An organic electroluminescent compound represented by the following formula 1:

• wherein
• X1 to X3 each independently represent CH or N, with a proviso that at least one of X1 to X3 are N;
• Ar1 and Ar2 each independently represent a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl;
• Ar3 and Ar4 each independently represent hydrogen, deuterium, a halogen, a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, a substituted or unsubstituted (5- to 30-membered)heteroaryl, a substituted or unsubstituted (3- to 7-membered) heterocycloalkyl, or a substituted or unsubstituted (C3-C30)cycloalkyl;
• L1 represents a single bond, a substituted or unsubstituted (C6-C30)arylene, or a substituted or unsubstituted (5- to 30-membered)heteroarylene;
• R1 and R2 each independently represent a substituted or unsubstituted (C1-C30)alkyl, a substituted or unsubstituted (C6-C30)aryl, or a substituted or unsubstituted (5- to 30-membered)heteroaryl;
• or are linked to each other to form a substituted or unsubstituted, mono- or polycyclic, (C3-C30) alicyclic, aromatic ring, or a combination thereof, whose carbon atom(s) may be replaced with at least one heteroatom selected from nitrogen, oxygen, and sulfur;
• a represents an integer of 1 to 5, and b represents an integer of 1 to 4, in which if a and b represent an integer of 2 or more, each Ar3 and each Ar4 may be the same or different;
• and
• the heteroaryl(ene) and the heterocycloalkyl contain at least one heteroatom selected from B, N, O, S, Si, and P.