Retinoic acid receptor agonist, preparation method therefor, intermediate, pharmaceutical composition and use

A compound of formula (I):

• or a tautomer thereof, a stereoisomer thereof, an isotope derivative thereof, or a pharmaceutically acceptable salt thereof;
• wherein
• R1, R2, and R3 are each independently C1-6 alkyl;
• or, any two of R1, R2, and R3, together with the Si atom to which they are attached, form a 4- to 12-membered heterocycloalkyl ring, wherein the 4- to 12-membered heterocycloalkyl ring comprises 1, 2, 3, or 4 heteroatoms independently selected from Si, N, O, and S;
• R4 is C1-6 alkyl, —NR4aR4b, or —SiR4cR4dR4e;
• or, R4 and any one of R1, R2, and R3, together with the atom to which they are attached, render
• form
• R4a and R4b are each independently C1-6 alkyl;
• or, R4a and R4b, together with the N atom to which they are attached, form a 4- to 6-membered heterocycloalkyl ring, and the 4- to 6-membered heterocycloalkyl ring comprises 1, 2, or 3 N atoms;
• R4c, R4d, and R4e are each independently C1-6 alkyl;
• ring A, ring B, and ring C are each independently a 4- to 12-membered heterocyclic ring, and the 4- to 12-membered heterocyclic ring comprises 1, 2, 3, or 4 heteroatoms independently selected from Si, N, O, and S;
• R4f, R4g, or R4h are each independently C1-6 alkyl;
• m, n, and q are each independently 0, 1, 2, or 3;
• R5 is C1-6 alkoxy or C1-6 alkoxy substituted by one or more than one R5a;
• each R5a is independently halogen or hydroxyl;
• R6 is H or C1-6 alkyl.