Can relief of ring-strain in a cyclopropylmethyllithium drive the Brook rearrangement?
作者:Jonathan Clayden、David W. Watson、Mark Chambers
DOI:10.1016/j.tet.2004.10.099
日期:2005.3
2]-Brook rearrangement led to α-silyloxy organolithiums which on warming underwent cyclopropane ringopening and [1,5]-retro-Brook rearrangement to yield γ-silyl ketones. Despite the favourability of the cyclopropane ringopening, the Brookrearrangement still required the presence of an anion stabilising group to proceed. β-Silylketones were similarly formed by Brook–retro-Brook rearrangement on warming
3-dithianes using 30% hydrogen peroxide catalyzed by iron(III) acetylacetonate–sodium iodide. The use of niobium(V) chloride as a catalyst instead of iron(III) acetylacetonate was also effective, except in synthesizing some acyltrimethylsilanes. Acylsilanes were obtained efficiently from dedithioacetalization of 2-silylated 1,3-dithianes using 30% hydrogen peroxide catalyzed by iron(III) acetylacetonate–sodium
Lewis Acid-Assisted Photoinduced Intermolecular Coupling between Acylsilanes and Aldehydes: A Formal Cross Benzoin-Type Condensation
作者:Kento Ishida、Fumiya Tobita、Hiroyuki Kusama
DOI:10.1002/chem.201704776
日期:2018.1.12
by Lewis acid is highly important to realize this reactionefficiently, otherwise the yield of the desired coupling products were significantly decreased. Noteworthy is that a formal cross benzoin‐type reaction using acylsilanes was achieved under Lewis acidic conditions. This is the first example of Lewis acid‐catalyzed reaction of photochemically generated siloxycarbenes with electrophiles.