36306-62-4Relevant academic research and scientific papers
Cycloadditions of allylsilanes, Part 14: Enantiospecific synthesis of bicyclo[4.3.0]nonanes by asymmetric [3+2] cycloaddition of chiral allylsilanes
Knoelker, Hans-Joachim,Foitzik, Norbert,Schmitt, Oliver
, p. 3557 - 3560 (1999)
The titanium tetrachloride promoted [3+2] cycloaddition of (R)-(1- phenylprop-2-enyl)trimethylsilane (R)-4 (82% ee) and 1-acetylcyclohexene 1 provides an enantiospecific route to the bicyclo[4.3.0]nonane (+)-6.
Access to functionalized bicyclo[4,3,0]nonenes via palladium-catalyzed oxidative cyclization of 2-allylcyclohexyl oximes
Zhu, Jia-Liang,Wu, Sih-Ting,Shie, Jr-Yun
, p. 3623 - 3633 (2014)
A new palladium-catalyzed oxidative cyclization process leading to the functionalized bicyclo[4,3,0]nonenes is serendipitously discovered during attempts to form aza-heterocycle by the amino-Heck reaction of trans-2-vinylclohexyl phosphinyloxime. Under the influence of Pd(dba) 2/Et3N/1:1 N2-O2 (1:1, v/v) (Method A) or Pd(OAc)2/Et3N/O2 (Method B), the reactions afford the substituted cis-1-hydroxyl-8-formyl-bicyclo[4,3,0]non-8(9)- enes or bicycle[4,3,0]non-1(9)-en-8-ones in varying yields with the incorporation of molecular oxygen into the structures. The 5,6-bicyclic scaffold of these products is presumably derived from tandem double intramolecular cyclization followed by the ring-opening of an aza-palladium(II) tricyclic intermediate.
[3+2] Cycloadditions of allylsilanes - 4. Dual reactivity of allyltrimethylsilane: Sakurai reaction versus trimethylsilylcyclopentane annulation
Knolker,Foitzik,Graf,Pannek,Jones
, p. 9955 - 9972 (1993)
The Lewis-acid-promoted reaction of allyltrimethylsilane with enones is shown to afford the 3-allyl ketone derivatives (Sakurai products) along with the trimethylsilylcyclopentanes ([3+2] cycloaddition products). The stereochemistry of the [3+2] cycloaddi
Rhodium-Catalyzed Intramolecular Cyclopropanation of α-Diazo β-Keto Nitriles Containing an Unsaturated Substituted Cycloalkyl Group
Zhu, Jia-Liang,Wu, Yung-Peng
, p. 1467 - 1472 (2017/07/22)
Several α-diazo β-keto nitriles bearing trans -2-allyl-, -vinyl-, or -phenylcycloalkyl groups were prepared and their intramolecular cyclopropanation reactions were examined. In the presence of Rh 2 (OAc) 4 (1 mol%) as a catalyst, th
Route to Highly Substituted Pyridines
Hilf, Justin A.,Holzwarth, Michael S.,Rychnovsky, Scott D.
, p. 10376 - 10382 (2016/11/17)
Pyridine rings are common structural motifs found in a number of biologically active compounds, including some top-selling pharmaceuticals. We have developed a new approach to access substituted pyridines. The method aims to provide a reliable synthesis of a diverse range of substituted pyridines through a three-step procedure. Readily available enones are first converted into 1,5-dicarbonyls through a two-step Hosomi-Sakurai allylation/oxidative cleavage sequence, which is followed by subsequent cyclization to the corresponding pyridine using hydroxylamine hydrochloride. A variety of substituted pyridines have been synthesized using this method.
Highly stereoselective synthesis of bicyclo[n.3.0]alkanes by titanium tetrachloride promoted [3 + 2] cycloaddition of allylsilanes and 1-acetylcycloalkenes
Knoelker, Hans-Joachim,Foitzik, Norbert,Goesmann, Helmut,Graf, Regina,Jones, Peter G.,Wanzl, Guenter
, p. 538 - 551 (2007/10/03)
The titanium tetrachloride promoted reaction of allylsilanes 1 with 1-acetylcyclohexene is shown to afford the silylbicyclo[4.3.0]nonanes 9 ([3 + 2] cycloaddition products) along with the 1-acetyl-2-allylcyclohexane 4 (Hosomi-Sakurai product). Here we report that systematic variation of the substituents at the silicon atom of 1 allows suppression of the classical Hosomi Sakurai reaction in favor of the [3+2] cycloaddition. Cycloaddition of the allylsilanes 1d, 1i, and 1k with 1-acetylcycloalkenes 10, containing a 5-, 6-, 7-, 8-, or 12-membered ring, gives rise to the corresponding silylbicyclo[n.3.0]alkanes 11-13. The cycloaddition of allyltriisopropylsilane (1k) and 1-acetyl-2-methylcycloalkenes 15 provides silylbicyclo[n.3.0]alkanes 16 with two contiguous quaternary carbon centers. The stereochemistry of the silylbicyclo[n.3.0]alkanes 11a-c and 14 is unambiguously determined by X-ray analysis and 13C NMR spectroscopy.
Neighboring Group Participation in Lewis Acid-Promoted and Annulations. The Stereocontrolled Synthesis of Tricyclic Ethers
Molander, Gary A.,Cameron, Kimberly O.
, p. 5931 - 5943 (2007/10/02)
A variety of 1,4- and 1,5-keto aldehydes derived from cycloalkanes are coupled with the bis(trimethylsilyl) enol ether of methyl acetoacetate in the presence of either TMSOTf or TrSbCl6 to generate tricyclic ethers.The reactions proceed with excellent regiochemical control by a mechanism involving neighboring group participation.This mechanism involves initial formation of a bicyclic oxocarbenium ion intermediate from the keto aldehyde substrates.The geometries of selected bicyclic intermediates have been optimized using the AM1 method allowing successful prediction of the stereochemical outcomes in the cyclization in most cases.Epimerization of α-chiral keto aldehyde substrates does not appear to occur in these Lewis acid-promoted annulation reactions.
Five-Membered Ring Annulation vis Propargly- and Allylsilanes
Danheiser, Rick L.,Dixon, Brian R.,Gleason, Robert W.
, p. 6094 - 6097 (2007/10/02)
Allyl- and propargylsilanes can serve as three-carbon components in a annulation strategy for the synthesis of five-membered carbocycles and heterocycles.
