Direct Syn Addition of Two Silicon Atoms to a C≡C Triple Bond by Si−Si Bond Activation: Access to Reactive Disilylated Olefins. Issue 9 (23rd January 2017) - Ahmad, Maha
Abstract: A catalytic intramolecular silapalladation of alkynes affords, in good yields and stereoselectively, syn ‐disilylated heterocycles of different chemical structure and size. When applied to silylethers, this reaction leads to vinylic silanols that undergo a rhodium‐catalyzed addition to activated olefins, providing the oxa‐Heck or oxa‐Michael products, depending on the reaction conditions. Abstract : Disilylated olefins were obtained by a selective Si−Si bond palladium activation followed by intramolecular addition of two silicon atoms to the C≡C triple bond, thereby accessing a family of new silaheterocycles. The reaction affords vinylic silanols that engage in rhodium‐catalyzed oxa‐Heck or oxa‐Michael additions. Tuning of the experimental conditions allows promotion of the preferred addition reaction.