Synthesis of unsymmetrically and symmetrically functionalized disiloxanes via subsequent hydrosilylation of C & EQUIV;C bonds

A selective synthesis of unsymmetrically functionalized disiloxanes via the subsequent hydrosilylation of internal alkynes in the first step, and alkynes (terminal or internal) or 1,3-diynes in the second, with 1,1,3,3-tetramethyldisiloxane (1) is presented for the first time. Using developed approaches performed in a stepwise or one-pot manner a new family of disubstituted disiloxanes was obtained which had previously been inaccessible by other synthetic methods. Moreover, symmetrically functionalized disiloxanes were obtained by direct hydrosilylation of 2 equivalents of terminal or internal alkynes with 1, showing the unique versatility of the hydrosilylation process. Three examples of symmetric disiloxanes were characterized by single crystal X-ray diffraction for the first time. As a result, a wide group of new compounds which can find potential applications as building blocks or coupling agents was obtained and characterized.

Automated summary

A selective method for synthesizing unsymmetrically functionalized disiloxanes was developed, involving the hydrosilylation of internal alkynes followed by the hydrosilylation of alkynes or 1,3-diynes with 1,1,3,3-tetramethyldisiloxane. This strategy allowed the preparation of a new family of disubstituted disiloxanes that were previously inaccessible by other synthetic methods. Symmetrically functionalized disiloxanes were also obtained by directly hydrosilylating terminal or internal alkynes, demonstrating the versatility of the hydrosilylation process. The characterized compounds have the potential to be used as building blocks or coupling agents.