Is it permissible, from a Sharia perspective, to deal with what are known as "Convertible Notes," and if not, what modifications are required to make them compliant with Sharia?

Bonds: These are certificates by which the issuer commits to paying the holder the nominal value upon maturity. Convertible bonds are bonds that can be converted into shares. Trading in bonds of all types is forbidden as long as they represent a debt on which conditional interest accrues, because they are usurious loans. Legitimate alternatives to usurious bonds include Mudarabah bonds and Ijarah sukuk.