Possible Clues:

• White against black? The chairman will have something to say about that!
• Important corporate event (2 words)
• High-level get-together, or an apt description of the pairing found in 19-, 25-, 30-, 48-, or 56-Across?
• Good name for a carpentry dating site?
• Well-spoken director making contact with those discussing what's happening in The Corporation
• Where strategies are devised for a chess match?
• Executive session
• Surfers' reunion?
• What have the mortise and tenon contributed to business culture?