10203-33-5Relevant academic research and scientific papers
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.
Zirconium Mediated Regioselective Carbon-Carbon Bond Formation Reactions
Takahashi, Tamotsu,Suzuki, Noriyuki,Hasegawa, Maki,Nitto, Yu,Aoyagi, Ko-ichiro,Saburi, Masahiko
, p. 331 - 334 (1992)
Reactions of zirconocene-alkene complexes with aldehydes gave alcohols as coupling products after hydrolysis.The carbon-carbon bond formation proceeded at C1 carbon of alkenes, in sharp contrast to the reactions of alkene-alkene coupling on zirconium.A similar alcohol was also obtained by the reaction of zirconacyclopentane with aldehyde after hydrolysis.Treatment of (C5Me5)2ZrEt2 with styrene gave 2-phenylbutane after hydrolysis contrary to the case of Cp2ZrEt2 which afforded 1-phenylbutane.
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.
CYP505E3: A Novel Self-Sufficient ω-7 In-Chain Hydroxylase
Maseme, Mpeyake Jacob,Opperman, Diederik Johannes,Pennec, Alizé,Smit, Martha Sophia,van Marwijk, Jacqueline
supporting information, p. 10359 - 10362 (2020/04/23)
The self-sufficient cytochrome P450 monooxygenase CYP505E3 from Aspergillus terreus catalyzes the regioselective in-chain hydroxylation of alkanes, fatty alcohols, and fatty acids at the ω-7 position. It is the first reported P450 to give regioselective in-chain ω-7 hydroxylation of C10–C16 n-alkanes, thereby enabling the one step biocatalytic synthesis of rare alcohols such as 5-dodecanol and 7-tetradecanol. It shows more than 70 percent regioselectivity for the eighth carbon from one methyl terminus, and displays remarkably high activity towards decane (TTN≈8000) and dodecane (TTN≈2000). CYP505E3 can be used to synthesize the high-value flavour compound δ-dodecalactone via two routes: 1) conversion of dodecanoic acid into 5-hydroxydodecanoic acid (24 percent regioselectivity), which at low pH lactonises to δ-dodecalactone, and 2) conversion of 1-dodecanol into 1,5-dodecanediol (55 percent regioselectivity), which can be converted into δ-dodecalactone by horse liver alcohol dehydrogenase.
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.
A new type of complex reagent, R4Pb / TiCl4
Yamamoto, Yoshinori,Yamada, Jun-Ichi,Asano, Tetsuya
, p. 5587 - 5596 (2007/10/02)
Tetraalkllleads (R4Pb) reacted quite smoothly with aldehydes R'CHO in the presence of TiCl4 to produce the corresponding alcohols (RCHOHR′) in high to good yields. The reagent system, R4Pb/ TiCl4, exhibited high chemoselectivity; only aldehydes underwent the alkylation in the presence of ketones. Further, the new reagent exhibited high 1,2- and 1,3-asymmetric induction. The transfer order of alkyl groups in the reaction of aldehydes with mixed tetraalkylleads/TiCl4 was determined; Me>Et.i-Pr?n-Bu.
Dimethylboron Bromide and Diphenylboron Bromide: Cleavage of Acetals and Ketals
Guindon, Yvan,Yoakim, Christiane,Morton, Howard E.
, p. 3912 - 3920 (2007/10/02)
The cleavage of various acetal and ketal derivatives by the use of dialkyl- and diarylboron halides is described.Acetals and ketals readily react with dimethylboron bromide or diphenylboron bromide at -78 deg C to give the corresponding carbonyl compounds in excellent yield.Under similar reaction conditions MEM, MOM, and MTM ethers are smoothly converted to alcohols.Acetonides are also cleaved with dimethylboron bromide while THP and THF ethers and methyl glycosides react at room temperature.Mechanistic considerations of the cleavage reactions are presented.The chemoselective virtues of dimethylboron bromide are summarized.
