Carol Vogel names the buyer of the $142m Francis Bacon triptych based upon her sources:

Those who believed the mysterious buyer was Stephen A. Wynn, the Las Vegas casino owner, were not far off. Art world sources now say the buyer was his ex-wife, Elaine Wynn. A co-founder of the Wynn Casino Empire. As of September, Forbes put her net worth at $1.9 billion.

Buyer of $142.4 Million Bacon Triptych Identified as Elaine Wynn (NYTimes)