1569-59-1Relevant articles and documents
Alkenes as chelating groups in diastereoselective additions of organometallics to ketones
Raffier, Ludovic,Gutierrez, Osvaldo,Stanton, Gretchen R.,Kozlowski, Marisa C.,Walsh, Patrick J.
, p. 5371 - 5377 (2014)
Alkenes have been discovered to be chelating groups to Zn(II), enforcing highly stereoselective additions of organozincs to β,γ-unsaturated ketones. 1H NMR studies and DFT calculations provide support for this surprising chelation mode. The results expand the range of coordinating groups for chelation-controlled carbonyl additions from heteroatom Lewis bases to simple C-C double bonds, broadening the 60 year old paradigm.
PROCESS FOR PREPARING PLATINUM ORGANOSILOXANE COMPLEXES USING AN ENONE ADDITIVE
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Paragraph 0024, (2019/02/06)
A platinum organosiloxane complex is prepared by a process including combining A) a platinous halide; B) a ketone; C) an enone additive distinct from any other starting materials or rearrangement products thereof; and D) a polyorganosiloxane having, per molecule, 2 to 4 silicon bonded terminally unsaturated hydrocarbon groups having from 2 to 6 carbon. The platinum organosiloxane complex prepared by the process is useful as a hydrosilylation catalyst.
STEREOCHEMICAL AND SPECTROSCOPIC STUDIES ON THE REACTION OF ALLYLSTANNANES WITH ALDEHYDES
Denmark, Scott E.,Weber, Eric J.,Wilson, Thomas M.,Willson, Timothy M.
, p. 1053 - 1066 (2007/10/02)
The orientational preference for the reacting double bonds in the Lewis acid-induced reaction of allylic stannanes and aldehydes has been examined.Model system 1 shows a strong and Lewis-acid independent preference for the synclinal orientation of double
Ring cleavage rearrangement of methyl-sunbstituted cyclopropylmethylboranes
Hill, E. Alexander,Park, Young-Whan
, p. 1 - 16 (2007/10/02)
2,2,3-Trimethyl- and 2,3-dimethylenecyclopropane were prepared and hydroborated using various borane reagents.Changes in the borane solutions as a result of heating were studied by NMR and by oxidation to alcohols.Ring-cleavage rearrangement reactions were observed, analogous to rearrangements previously found for cyclopropylmethyl Grignard reagents and for unsubstituted cyclopropylmethylboranes.Methyl substitution slows the rearrangement involving cleavage of the bond to the substituted ring carbon, and has an especially large effect when cis to the metallomethyl group.In the 2,2,3-trimethylcyclopropylmethyl system, the ring-cleavage rearrangement does not go to completion, but instead approaches an equilibrium in which a substantial concentration of the trans isomer remains.Rearrangement in the 2,3-dimethylcyclopropylmethyl system occurs with retention of configuration at the ring carbon to which the boron migrates.The results of the present work suggest a mechanistic reinterpretation of the carboboration of bicyclobutane.
Regioreversed Addition of Crotylmagnesium Chloride to Carbonyl Compounds in the Presence of AlCl3
Yamamoto, Yoshinori,Maruyama, Kazuhiro
, p. 1564 - 1565 (2007/10/02)
The reaction of carbonyl compounds with crotylmagnesium chloride in the presence of AlCl3 at -78 deg C gives predominantly products in which the allylic group is attached at the less substituted position (α-adduct).
HOMOLYTIC DISPLACEMENT AT CARBON. V. FORMATION OF CYCLOPROPYLCARBINYLSULPHONES AND TRICHLOROETHYLCYCLOPROPANES FROM BUT-3-ENYL COBALOXIMES BY A NOVEL PROCESS INVOLVING HOMOLYTIC ATTACK AT THE δ-CARBON OF THE BUTENYL LIGAND
Ashcroft, Martyn R.,Bury, Adrian,Cooksey, Christopher J.,Davies, Alwyn G.,Gupta, B. Dass,et al.
, p. 89 - 104 (2007/10/02)
But-3-enyl- and substituted but-3-enylcobaloximes react with bromotrichlormethane (or trichloromethanesulphonyl chloride) and with 4-toluenesulphonyl chloride thermally or photochemically to give good yields of β,β,β-trichloroethylcyclopropanes and cyclopropylcarbinyl(tolyl)sulphones, respectively.The reactions proceed by a chain mechanism in which a key step is a novel process in which homolytic attack of a trichloromethyl or 4-toluenesulphonyl radical at the δ-carbon of the butenyl ligand leads to synchronous or subsequent attack of the incipient γ-carbon radical on the α-carbon, causing cyclisation and displacement of cobaloxime(II).The other propagation step involves the reaction of the cobaloxime(II) with the bromotrichloromethane, trichloromethanesulphonyl chloride or 4-toluenesulphonyl chloride to give the reactive organic radical.
