The "twelve princes" in Genesis 17:20 may have been named in a later passage as sons of Ishmael, Genesis 25:12-18:

¹² These are the generations of Ishmael, Abraham's son, whom Hagar the Egyptian, Sarah's servant, bore to Abraham. ¹³ These are the names of the sons of Ishmael, named in the order of their birth: Nebaioth, the firstborn of Ishmael; and Kedar, Adbeel, Mibsam, ¹⁴ Mishma, Dumah, Massa, ¹⁵ Hadad, Tema, Jetur, Naphish, and Kedemah. ¹⁶ These are the sons of Ishmael and these are their names, by their villages and by their encampments, twelve princes according to their tribes. ¹⁷ (These are the years of the life of Ishmael: 137 years. He breathed his last and died, and was gathered to his people.) ¹⁸ They settled from Havilah to Shur, which is opposite Egypt in the direction of Assyria. He settled over against all his kinsmen.

Their names also appear in 1 Chronicles 1:28-31, written much later in the 5th century BC:

²⁸ The sons of Abraham: Isaac and Ishmael. ²⁹ These are their genealogies: the firstborn of Ishmael, Nebaioth, and Kedar, Adbeel, Mibsam, ³⁰ Mishma, Dumah, Massa, Hadad, Tema, ³¹ Jetur, Naphish, and Kedemah. These are the sons of Ishmael.

The book of Genesis contains materials believed to originate from the time of Moses (1500-1300 BC) with the final redaction no later than the 5th century BC. Abraham and Ishmael themselves are believed to live around 2100-1900 BC. So the two Genesis passages above predate the time of the twelve imams by at least 1100 years. If the twelve princes were the ancestors of the twelve imams, there was at least a 2500 year gap between them.

Another interpretation that you may have in mind is that the "twelve princes" in Gen 17:20 is a prophecy for the twelve imams who live 2500 years later, or a typology similar to how in Christianity some passages in the prophetic books obtain a second meaning when applied to Jesus centuries later. But as far as I know, no Christian theology interpret Gen 17:20 that way.