91899-33-1Relevant academic research and scientific papers
Visible-Light Photoredox-Catalyzed α-Regioselective Conjugate Addition of Allyl Groups to Activated Alkenes
Gontala, Arjun,Woo, Sang Kook
, p. 3223 - 3228 (2020/07/06)
The α-regioselective conjugate addition of allyl groups to activated alkenes is a poorly explored area of research. Herein, we report an α-adduct and (E)-isomer selective conjugate addition of allylsilanes to activated alkenes by visible-light photoredox catalysis. The reaction involves allylic radicals that can be generated from allylsilanes through a photoinduced single-electron transfer mechanism. (Figure presented.).
Cobalt-catalyzed mono-coupling of R3SiCH2MgCl with 1,2-dihalogenoethylene: A general route to γ-substituted (E)-allylsilanes
Kamachi, Taku,Kuno, Akiko,Matsuno, Chikashi,Okamoto, Sentaro
, p. 4677 - 4679 (2007/10/03)
The reaction of trimethylsilylmethylmagnesium chloride (TMSCH 2MgCl) with 1,2-dihalogenoethylene in the presence of 1mol% of Co(II) or Co(III) acetylacetonate in THF or THF-NMP proceeded exclusively in a mono-coupling pathway to provide 3-trimethylsilyl-1-halogeno-1-propene with >99% of E geometry in high yield, which was converted to a variety of γ-substituted allylsilanes by Ni- or Pd-catalyzed coupling with organometallic compounds.
Desilylation and conversion of trimethylsilylmethyl epoxides into ketones under the influence of a bulky base
Ma, Yuan
, p. 310 - 315 (2007/10/03)
Trimethylsilylmethyl epoxides were converted into ketones through a desilylation, epoxide ring-opening, and rearrangement reaction under the influence of a bulky base in the presence of 18-crown-6.
Synthesis of Optically Active Secondary Allylic Alcohols from Allylsilanes via Successive Asymmetric Dihydroxylation (AD) and Peterson Olefination Reaction
Okamoto, Sentaro,Tani, Kousuke,Sato, Fumie,Sharpless, K. Barry,Zargarian, Davit
, p. 2509 - 2512 (2007/10/02)
Optically active, secondary allylic alcohols can be prepared from allylic silanes by the successive asymmetric dihydroxylation and Peterson olefination reactions.The effects of trialkylsilyl groups on the outcome of the AD reaction on vinyl and allyl silanes are also discussed.
Stereoselective Synthesis of (E)- and (Z)-2-Alkenyltrimethylsilanes from 1,2-Epoxy-1,3-bis(trimethylsilyl)propane
Shimizu, Nobujiro,Imazu, Sachiko,Shibata, Fumihiro,Tsuno, Yuho
, p. 1122 - 1128 (2007/10/02)
Stereoselective synthesis of various (E)- and (Z)-2-alkenyltrimethylsilanes (RCH=CHCH2SiMe3; R=Me, Et, n-Bu, i-Pr, c-hexyl, t-butyl, and phenyl) has been accomplished by a reaction of 1,2-epoxy-1,3-bis(trimethylsilyl)propane with Grignard reagents (RMgX) followed by subsequent Peterson olefination reactions of resulting 1,2-bis(trimethylsilyl)-3-alkanols ; the acid (BF3OEt2 or HClO4)-catalyzed olefination yields the (E)-isomer, while the base (KH or NaH)-induced olefination yields the (Z)-isomer in more than 95 percent stereochemical purity in most cases.
A convenient synthesis of allyltrimethylsilanes from allylic phosphates
Gorzynski Smith,Henke,Mohler,Morgan,Rajan
, p. 1999 - 2006 (2007/10/02)
Treatment of an allylic phosphate with trimethylsilyllithium or trimethylsilylcopper [prepared from one equivalent of trimethylsilyllithium and copper (I) iodide] affords allyltrimethylsilanes in good - excellent yields with high stereoselectivity.
REGIO- AND STEREOSELECTIVE SYNTHESIS OF ALLYLTRIMETHYLSILANES VIA KRIEF-REICH ELIMINATION IN β-SELENO-γ-SILYL ALCOHOLS
Sarkar, Tarun K.,Ghosh, Sunil K.,Satapathi, Tushar K.
, p. 1885 - 1898 (2007/10/02)
The synthesis of (E)-allyltrimethylsilanes by regio- and stereocontrolled pathways is described based on the preference for Krief-Reich elimination over silicon-controlled rearrangement in β-seleno-γ-silyl alcohols, readily available from α-selenoaldehydes, 10 - 12.Usefulness of this protocol for the introduction of the allylsilane function α to the carbonyl group in cycloalkanones as well as for the preparation of unsymmetrically substituted allylsilanes is also reported.
SILICON-CONTROLLED REARRANGEMENT VERSUS KRIEF-REICH REACTION IN β-SELENO-γ-SILYL ALCOHOLS : A NEW STEREOSELECTIVE SYNTHESIS OF TERMINALLY-SUBSTITUTED ALLYLSILANES
Sarkar, Tarun K.,Ghosh, Sunil K.
, p. 2061 - 2064 (2007/10/02)
A new and efficient route to terminally-substituted (E)-allylsilanes is described based on the preference for Krief-Reich elimination in several β-seleno-γ-silyl alcohols, readily available by diastereoselective addition of various Grignard reagents or aldol reaction on 2-(phenylseleno)-3-(trimethylsilyl)propanal(9).
A HIGHLY STEREOSELECTIVE ROUTE TO 2-ALKENYLTRIMETHYLSILANES
Shimizu, Nobujiro,Shibata, Fumihiro,Tsuno, Yuho
, p. 1593 - 1594 (2007/10/02)
1,2-Epoxy-1,3-bis(trimethylsilyl)propane reacts with various Grignard reagents (RMgX) to give 1-R-2,3-bis(trimethylsilyl)-1-propanols which upon olefination with NaH or with BF3Et2O give the corresponding (Z) or (E)-2-alkenyltrimethylsilanes in moderate t
Regioselective Synthesis of Allyltrimethylsilanes from Allylic Halides and Allylic Sulfonates. Application to the Synthesis of 2,3-Bis(trimethylsilyl)alk-1-enes
Smith, Janice Gorzynski,Drozda, Susan E.,Petraglia, Susan P.,Quinn, Nina R.,Rice, Elizabeth M.,et al.
, p. 4112 - 4120 (2007/10/02)
The preparation of allyltrimethylsilanes by regioselective pathways is described.Treatment of (E)-1-chloro-2-alkenes with a reagent prepared from 1 equiv each of trimethylsilyllithium and copper(I) iodide in hexamethylphosphoramide to presumably form a (trimethylsilyl)copper reagent affords 3-(trimethylsilyl)-1-alkenes in good to excellent yields with a high regioselectivity.Treatment of these same 1-chloro-2-alkenes with (trimethylsilyl)lithium alone without added copper(I) iodide yields only (E)-1-(trimethylsilyl)-2-alkenes.A single allylic halide thus yields two regioisomeric allyltrimethylsilanes by proper choice of reaction conditions.The reaction of a variety of allylic sulfonates with (trimethylsilyl)copper has also been investigated.The mesylates of 2 deg and 3 deg allylic alcohols yield mixtures of isomeric allyltrimethylsilanes in which the 1-(trimethylsilyl)-2-alkenes predominate.With geraniol, the mesylate was prepared in situ and allowed to react with (trimethylsilyl)copper to afford two isomeric allyltrimethylsilanes in which the 3-(trimethylsilyl)-1-alkene predominates.Finally, these reactions have also been used to prepare a variety of 2,3-bis(trimethylsilyl)alk-1-enes, a class of unsaturated organosilanes which has received little attention in the literature.
