A new attachment/cleavage strategy: Polymer-bound allylic sulfones in a solid-phase route to trisubstituted olefins

Sulfones in Solid‐Phase Heterocycle Synthesis

“…8c, 14,15,44,49 The diverse cleavage strategies that can be applied to cleave substrates from sulfone linkers make them a versatile multifunctional linker. 8c, 14,15,44,49 The diverse cleavage strategies that can be applied to cleave substrates from sulfone linkers make them a versatile multifunctional linker.…”

Nucleophile Cleavable Linker Units

“…Recently, the design of polymer linkers as a rather [84] has been exemplified by the advent of 'leaving group linkers'. [85] Such linkers increase the synthetic efficiency by allowing a wider variety of bond formations at the linkage site. An efficient application of this concept was illustrated by the preparation of a immobilized benzotriazole linker (132) to exploit as a leaving group (Scheme 3.39).…”

CC Bond‐Forming Reactions

“…Kurth, Hwang et al [313,314] reported the preparation of sulfinate resin from styrene/2 % divinylbenzene as a novel traceless linker for SPOS. The conveniently prepared polymer-bound sulfinate (332) served as a starting material which can be alkylated with methyl or ethyl iodide in DME to give primarily the S-alkylated product (334) accompanied by only 3 % of O-alkylation product.…”

“…The remaining electron-deficient alkene residue may react with various nucleophiles. A Knoevenagel reaction with isonitrilo-acetates (341) or TOSMIC followed by cyclization leads to pyrrolines, which could readily eliminate the polymer-bound sulfinate to release pyrroles (342) [313] (Scheme 71).…”

“…First example of the Nicholas reaction [313] on a solid support. Various propargylic alcohols were immobilized on a Merrifield resin.…”