4.4.38.14 Propargylsilanes (Update 2022)

This review is an update to the earlier Science of Synthesis coverage of the synthesis of propargylsilanes (Section 4.4.38). It covers the literature published between 2000 and 2021.Propargylsilanes can be prepared by a rather large array of methods that rely either on reactions involving C–Si bond formation, or on the manipulation of organosilicon-containing precursors to install a C≡C triple bond. For the first strategy, electrophilic silylation of propargyl or allenyl metals by reaction with halosilanes is the most frequently encountered; however, approaches such as propargylic carbene insertions into hydrosilanes, nucleophilic substitution or addition reactions with silylboranes and other silylmetals, or the rearrangement of propargylic silyl ethers have been developed more recently to diversify the silicon source. For the second type of approach, in addition to established transformations such as alkynylation of silylmethyl halides, α-silyloxiranes, or acylsilanes, the allylic substitution of allylic phosphates or elimination reactions of heteroatom-substituted allylsilanes have also recently gained interest. Moreover, a large body of work has been devoted to accessing elaborated propargylsilanes from simple pre-existing propargylsilane units through functionalization at the acetylenic carbon. Given the relevance of propargylsilanes in the context of stereoselective synthesis, there is persistent interest in the preparation of chiral, nonracemic propargysilanes, and significant progress in this area has been achieved over the last two decades, notably through the implementation of asymmetric catalysis.