- The Rhodium-Catalyzed Hydroboration of Olefins: A Mechanistic Investigation
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Labeling studies carried out on the rhodium-catalyzed olefin hydroboration reaction reveal that the degree of reversibility of the elementary steps in the catalytic cycle is highly substrate dependent.The implications of these observations are discussed.
- Evans, David A.,Fu, Gregory C.
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- Direct Carbohydroxylation of Arylalkenes with Allylic Alcohols: Cooperative Catalysis of Copper, Silver, and a Br?nsted Acid
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The cooperative catalysis of copper, silver, and Br?nsted acid is presented as a new strategy for olefin functionalization. The catalytic direct carbohydroxylation of arylalkenes with allylic alcohols provided a straightforward and efficient approach for preparing 4,5-unsaturated alcohols. Synthetically useful functional groups, such as Cl, Br, carbonyl, and chloromethyl, remained intact during the functionalization reaction.
- Ahmed, Waqar,Zhang, Sheng,Yu, Xiaoqiang,Feng, Xiujuan,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 2495 - 2499
(2019/02/01)
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- New amine-stabilized deuterated borane-tetrahydrofuran complex (BD3-THF): convenient reagent for deuterium incorporations
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Convenient methods for the preparation of BD3-THF complex were developed. Certain amines stabilize the BD3-THF for long-term storage. Regioselectivity studies were carried out with the new amine-stabilized BD3-THF with rep
- Todd, Robert C.,Hossain, M. Mahmun,Josyula, Kanth V.,Gao, Peng,Kuo, John,Tan
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p. 2335 - 2337
(2007/10/03)
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- Functionalized organolithium compounds of DTBB-catalyzed sulfur-lithium exchange
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The successive reaction of β- or γ-hydroxy or amino phenyl thioethers (1,4) with butyllithium and an excess of lithium powder in the presence of a catalytic amount of DTBB in THF at - 78°C leads to the formation of the corresponding β- or γ-functionalized organolithium compounds 2 or 5, respectively, which by treatment with different electrophiles [D2O, t- BuCHO, PhCHO, Me2CO, (CH2)4CO, (CH2)5CO] at temperatures ranging between - 78°C and room temperature yields, after hydrolysis with water, the expected functionalized alcohols or amines 3 or 6, respectively, in a completely regioselective manner.
- Foubelo, Francisco,Gutiérrez, Ana,Yus, Miguel
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p. 503 - 514
(2007/10/03)
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- β-Functionalised organolithium compounds through a sulfur-lithium exchange
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The successive reaction of different β-hydroxy or β-amino tbioethers 1a-d with n-butyl-lithium and an excess of lithium powder and a catalytic amount of DTB in THF at -78°C leads to the formation of the corresponding β-functionalised organolithium compounds 2a-d, which by reaction with several electrophiles [D2O, Bu(t)CHO, PhCHO, Me2CO, (CH2)5CO] at temperatures ranging between -78 and 20°C yields, after hydrolysis with water, the expected functionalised alcohols or amines 3aa-de in a regioselective manner.
- Foubelo, Francisco,Gutierrez, Ana,Yus, Miguel
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p. 4837 - 4840
(2007/10/03)
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- β-Substituted Organolithium Compounds from Chlorohydrins: Application to the Direct Synthesis of Bifunctionalized Organic Cpmpounds
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The reaction of different chlorohydrins with n-butyl-lithium at -78 deg C followed by metallation wiht lithium naphthalenide at the same temperature leads to very reactive organolithium compounds bearing an alkoxide function at the β-position with respect to metal.The reaction of these intermediates with several electriphiles leads to mono- as well as bi-functionalized organic compounds.Thus, treatment of these dianions with deuterium oxide, oxygen, carbon dioxide, benzyl bromide, dimethyl disulphide, and carbonyl compounds, gave 2-deuterioalcohols, 1,2-diols, β-hydroxy-acids, 2-benzyl alcohols, 2-hydroxy-thioethers, and 1,3-diols respectively.The preparation of β-substituted organolithium derivatives can be alternatively carried out starting from α-chloroketones by the same procedure.When the lithium atom is linked to a secondary carbon atom the dianions are very unstable and decompose, even at -100 deg C, by β-elimination yielding the corresponding olefins.
- Barluenga, Jose,Florez, Josefa,Yus, Miguel
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p. 3019 - 3026
(2007/10/02)
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- β-Substituted Organolithium Compounds; Direct Preparation and Reactivity
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Very reactive organolithium compounds bearing an alkoxide function at the β-position with respect to the metal are obtained by direct metallation with lithium naphthalenide at low temperature of the corresponding lithium chlorohydrin salt; the reaction of these dianions with different electrophilic agents leads to the corresponding mono- and bi-functionalized compounds.
- Barluenga, Jose,Florez, Josefa,Yus, Miguel
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p. 1153 - 1154
(2007/10/02)
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