text: Many modifications to the Hiyama coupling have been developed that avoid the use of a fluoride activator/base. Using organochlorosilanes, Hiyama found a coupling scheme utilizing NaOH as the basic activator. Modifications using alkoxysilanes have been reported with the use of milder bases like NaOH  and even water. Study of these mechanisms have led to the development of the Hiyama–Denmark coupling which utilize organosilanols as coupling partners.<br />  
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  Another class of fluoride-free Hiyama couplings include the use of a Lewis acid additive, which allows for bases such as KPO to be utilized, or for the reaction to proceed without a basic additive. The addition of a copper co-catalyst has also been reported to allow for the use of a milder activating agent and has even been shown to get turnover in which both the palladium(II) and copper(I) turnover in the catalytic cycle rather than addition of stoichiometric Lewis acid (e.g. silver(I), copper(I)).