10203-33-5Relevant articles and documents
DIMETHYLBORON BROMIDE AND DIPHENYLBORON BROMIDE. ACETAL AND KETAL CLEAVAGE. CLEAVAGE OF MEM, MOM AND MTM ETHERS.
Quindon, Yvan,Morton, Howard E.,Yoakim, Christiane
, p. 3969 - 3972 (1983)
A general and efficient procedure for the cleavage of acetals and ketals by the use of dimethylboron bromide or diphenylboron bromide is described.Under similar reaction conditions, MEM, MOM and MTM ethers also react to afford the parent alcohols in excellent yields.
Highly regioselective reaction of zirconocene-alkene complexes with aldehydes or ketones
Suzuki, Noriyuki,Rousset, Christophe J.,Aoyagi, Koichiro,Kotora, Martin,Takahashi, Tamotsu,et al.
, p. 117 - 128 (1994)
Reactions of zirconocene-alkene complexes Cp2Zr(CH2=CHR)(PR'3) (R = H, Me, Et, SiR"3 or Ar) with aldehydes or ketones were investigated.Zirconocene-ethylene, -propylene or 1-butene complexes reacted with aldehydes or ketones at terminal carbons of alkenes to give the corresponding alcohols after hydrolysis with a high regioselectivity.A similar type of reaction product was also obtained by a reaction of zirconacyclopentanes with aldehydes.This reaction proceeded via β-β' carbon-carbon bond cleavage of zirconacyclopentanes.A reaction of zirconocene-vinylsilane complexes with ketones afforded 3-trimethylsilyl-1-oxa-2-zirconacyclopentanes with an excellent regioselectivity.Carbon-carbon bond formation occurred exclusively at the terminal carbon of vinylsilanes.Their corresponding γ-silylalcohols were obtained after hydrolysis.The products showed that vinylsilanes reacted with carbonyl compounds at the β-carbon to silyl group.It is in sharp contrast to the conventional reactions of vinylsilanes of which the α-carbon normally attacked electrophiles.The reactions of styrene and its derivatives with pentan-3-one on zirconium gave a mixture of two regioisomers.Substituents of alkenes tend to be in α-position to Zr in 1-oxa-2-zirconacyclopentanes.This orientation showed a different aspect of the formation of 1-oxa-2-zirconacyclopentanes from the alkene-alkene coupling reaction on zirconium.The regioselectivity of the reaction with carbonyl compounds decreased in this order; R = alkyl > silyl > aryl. Key words: Zirconium; Silicon; Metallocenes; Carbon-carbon bond formation; Aldehyde; Ketone
Switchable β-alkylation of secondary alcohols with primary alcohols by a well-defined cobalt catalyst
Ding, Keying,Pandey, Bedraj,Xu, Shi
supporting information, p. 1207 - 1212 (2021/05/29)
β-alkylation of secondary alcohols with primary alcohols to selectively generate alcohols by a well-defined Co catalyst is presented. Remarkably, a low catalyst loading of 0.7 mol % can be employed for the reaction. More significantly, this study represents the first Co-catalyzed switchable alcohol/ketone synthesis by simply manipulating the reaction parameters. In addition, the transformation is environmentally friendly, with water as the only byproduct.
Samarium(II) triflate as a new reagent for the grignard-type carbonyl addition reaction
Fukuzawa, Shin-Ichi,Mutoh, Keisuke,Tsuchimoto, Teruhisa,Hiyama, Tamejiro
, p. 5400 - 5405 (2007/10/03)
On treatment of a THF solution of Sm(OTf)3 with 1 equiv of an organolithium or organomagnesium reagent at ambient temperature, the purple or deep green solution of the divalent samarium triflate [Sm(OTf)2] was readily obtained. For this preparation, s-BuLi was the most effective as was evidenced by the reduction of 2-phenylethyl iodide in the presence of HMPA. The Sm(OTf)2 reagent mediated the Grignard-type reaction effectively in THF/HMPA; alkylation and allylation of ketones or aldehydes with alkyl, allyl, or benzyl halides proceeded via organosamarium intermediates. Diastereoselectivity of the samarium-Grignard reaction was examined using 2-methylcyclohexanone, 4-tert-butylcyclohexanone, and 2-phenylpropanal and was found to be higher in each case than that with SmI2. With 2-methylcyclohexanone, for example, Sm(OTf)2 gave the greatest ratio of axial alcohol:equatorial alcohol = 99:1, and SmI2 gave a ratio of 91:9. Halides containing an ester or a silyl group were reactive in the Reformatsky- or Peterson-type reaction, respectively, using the Sm(OTf)2 reagent.
