Copper(I) Iodide-Promoted Allylation of Allyl- and Vinyl-silanes Assisted by Intramolecular-Coordination

Abstract

The allylation products, 1-(2-pyridylthio)alk-1,5-dienes, were produced regioselectively when 1-(2-pyridylthio)-1-(trimethylsilyl)alk-2-enes were treated with allylic chlorides in the presence of CuI and KF. The similar reaction of 1-(2-pyridylthio)-1-(trimethylsilyl)alk-1-enes with allylic chlorides produced the 1,4-dienes with complete retention of configuration.

Copper(I)tert-Butoxide-Promoted 1,4 Csp2-to-O Silyl Migration: Generation of Vinyl Copper Equivalents and Their Stereospecific Cross-Coupling with Allylic, Aryl, and Vinylic Halides

“…Although Z -isomers of 3 are prepared via 1,4 O-to-C sp 2 silyl migration,7a the method requires multistep transformation. Therefore, we first established the stereoselective preparation of Z -3 by the reaction sequence similar to that employed for the synthesis of ( Z )-β-(tributylstannyl)-α,β-unsaturated ketones 10a…”

“…In the course of study on the preparation and synthetic application of group 14 vinylmetal species, we found that vinylsilanes possessing a 2-pyridylthio group at the carbon α to the trimethylsilyl group reacted with allylic halides in the presence of CuI−KF to produce the cross-coupling products 10e. We tentatively assume that the reaction proceeds through transmetalation of silicon to copper assisted by the intramolecular coordination of nitrogen to silicon.…”

Copper(I) tert-Butoxide-Promoted 1,4 Csp2-to-O Silyl Migration: Stereospecific Allylation of (Z)-γ-Trimethylsilyl Allylic Alcohols

“…Recently, we found that the vinylsilanes bearing a 2-pyridylthio group at the carbon α to the trimethylsilyl group reacted with allylic halides in the presence of CuI−KF to produce the cross-coupling products 5e. We tentatively assume that the reaction proceeds via transmetalation of silicon to copper assisted by the intramolecular coordination of nitrogen to silicon.…”

“…In connection with our continuous study on the preparation and reaction of group 14 vinylmetals, we were intrigued with the 1,4 C sp 2 -to-O silyl migration of conformationally rigid γ-trimethylsilyl allylic alcohols 1a and 1b . Unlike the reaction of cinnamyl alcohol derivative 1d described above, the treatment of 1a and 1b with a stoichiometric or catalytic amount of lithium tert -butoxide at room temperature for 24 h gave the cyclic silyl ethers 1-oxa-2-silacyclopent-3-enes 2a and 2b as sole products (Scheme ).…”

Copper-Catalyzed Allylation of Carbonyl Derivatives Using Allyl(2-pyridyl)silanes

“…The allylation did not take place without CsF. Thus, we are currently assuming that the beneficial role of the pyridyl group is to help the reacting CC bond to coordinate to copper through precoordination (complex-induced proximity effect), thereby facilitating the subsequent Si-to-Cu transmetalation to generate allylcopper species by the action of CsF 1 Synthesis, crystal structure, and reaction of Cu complex 4 . …”