105087-05-6Relevant articles and documents
Chirality Transfer in Gold(I)-Catalysed Direct Allylic Etherifications of Unactivated Alcohols: Experimental and Computational Study
Barker, Graeme,Johnson, David G.,Young, Paul C.,Macgregor, Stuart A.,Lee, Ai-Lan
supporting information, p. 13748 - 13757 (2015/09/22)
Gold(I)-catalysed direct allylic etherifications have been successfully carried out with chirality transfer to yield enantioenriched, γ-substituted secondary allylic ethers. Our investigations include a full substrate-scope screen to ascertain substituent effects on the regioselectivity, stereoselectivity and efficiency of chirality transfer, as well as control experiments to elucidate the mechanistic subtleties of the chirality-transfer process. Crucially, addition of molecular sieves was found to be necessary to ensure efficient and general chirality transfer. Computational studies suggest that the efficiency of chirality transfer is linked to the aggregation of the alcohol nucleophile around the reactive π-bound Au-allylic ether complex. With a single alcohol nucleophile, a high degree of chirality transfer is predicted. However, if three alcohols are present, alternative proton transfer chain mechanisms that Erode the efficiency of chirality transfer become competitive.
On the Mechanism of Organoaluminum-Promoted Claisen Rearrangement of Allylic Vinyl Ethers
Nonoshita, Katsumasa,Maruoka, Keiji,Yamamoto, Hisashi
, p. 541 - 545 (2007/10/02)
The organoaluminum-promoted Claisen rearrangement of allylic vinyl ethers has been mechanistically studied by two sets of experiments and the observed Z and E selectivity is best accounted for by two possible chair-like structures with R substituents axial and equatorial, respectively.
THE REACTION OF α,β-EPOXYSILANES WITH METALLATED ALKYLARYL SULPHONES. A NOVEL APPROACH TO ALLYLIC ALCOHOLS
Masnyk, Marek,Wicha, Jerzy
, p. 2497 - 2500 (2007/10/02)
Lithiated alkylaryl sulphones (2a-c) react with α,β-epoxysilane (1) to yield O-trimethylsilyl allylic alcohols (3a-c), predominantly as Z isomers.The BF3-assisted reaction followed by treatment of the adduct with nBu4NF affords allylic alcohols.
A NOVEL REACTION OF α-HALOEPOXIDES WITH TRIALKYLSTANNATES
Corey, L. D.,Singh, S. M.,Oehlschlager, A. C.
, p. 1821 - 1827 (2007/10/02)
The reaction of α-haloepoxides with zinc powder or reagents containing tialkylstannate anion yields allylic alcohols by anti elimination of carbon halogen and adjacent carbon epoxy oxygen bonds.Appreciable Z -> E isomerization occurs in both types of reactions but the experimental results indicate that the conversion of erythro α-bromoepoxides to E allylic alcohols by zinc or trialkylstannates shows sufficient sterospecificity to be synthetically useful.
sp2-Hybridized β-Substituted Organo-lithium, -sodium, and -potassium Dianions; Preparation, Stability, and Reactivity
Barluenga, Jose,Fernandez, Jose R.,Yus, Miguel
, p. 447 - 452 (2007/10/02)
The reaction of the substituted 2-chloroallyl alcohol (3a) with ethylmagnesium bromide followed by lithium was found to give the β-substituted organolithium derivative (4) of the type C=C().Intermediates of this type were also prepared directly from (E)-2-chlorocrotonaldehyde (2) or 2-chloroacrolein (19) by the same process using different Grignard reagents.The use of sodium or potassium as the metal in the second step of the process was found to give the corresponding organosodium or organopotassium derivative (24) or (25).A dilithiated dianion (26) was also obtained from the corresponding chlorohydrin (3d) by reaction with phenyl-lithium followed by lithium.These intermediates, which are stable species at room temperature, were found to react stereoselectively with electrophilic reagents leading to functionalized substituted allyl alcohols.The thermal stability of the lithiated dianion (4d) has also been investigated.
STEREO- AND REGIOSELECTIVITY IN IODO DIOL FORMATION FROM ACYCLIC ALLYLIC ALCOHOLS
Chamberlin, A. Richard,Mulholland, Robert L.
, p. 2297 - 2302 (2007/10/02)
Reaction of electrophiles with a variety of acyclic allylic alcohols was investigated.Both aqueous iodine and acetylhypoiodite convert certain alkenols into iodo diols and acetoxy iodo alcohols, respectively, with regio- and stereoselectivities as high as 99percent.Protection of alcohol group lowers the selectivity only slightly.Structural factors that control the regioselectivity of iodohydrin formation in these substrates have been delineated.Some of the iodo diols have been deiodinated, illustrating a simple two step procedure for converting allylic alcohols into threo-1,3-diols.
