Ian Workman, 58, from Turton, Lancashire was given a life sentence in 2011 for stabbing to death 55-year-old Susan Workman.
In 2014, the High Court ruled that Workman's sister-in-law and sons should receive her divorce settlement instead.
The Court of Appeal has now rejected Workman's attempt to halt this payment.
Mrs Workman's sister, Carol Forrester, and his two sons, Nicholas and Benjamin Workman, claimed that he killed their mother to get out of paying her half his fortune.
In law, someone who is criminally responsible for the death of another cannot benefit from the death and they claimed this should also apply to financial proceedings in divorce cases.
In 2014, the High Court agreed that Workman should not be able to avoid paying the £1.5m award in his ex-wife's favour.
Workman then applied to the Court of Appeal to challenge two orders - one required him to disclose his assets and stopped him from defending the value of the claim while the other rejected his bid for a re-listing of an application to "freeze" his assets.
Dismissing both challenges, the Court of Appeal said there was a "persistent failure" by Workman to comply with the disclosure order.
His "flagrant contempt" in failing to comply had the potential to frustrate the damages assessment and could not be ignored.
Millionaire car dealer Workman was jailed for life in December 2011, with the judge recommending he served a minimum of 17 years.
Preston Crown Court heard Workman stabbed his ex-wife of 35 years once in the chest as she typed an account of their rows on her laptop, including descriptions of his abusive behaviour.
A man who murdered his ex-wife during a divorce dispute has lost a legal bid to stop his sister-in-law and two sons from receiving a £1.5m settlement.