58705-82-1Relevant academic research and scientific papers
Coordination-Induced Stereocontrol over Carbocations: Asymmetric Reductive Deoxygenation of Racemic Tertiary Alcohols
Isomura, Mayuko,Petrone, David A.,Carreira, Erick M.
supporting information, p. 4738 - 4748 (2019/03/19)
The inherent difficulty in eliciting facial control over carbocations has limited their utility as intermediates in asymmetric catalysis. We have now shown that a docking strategy involving the reversible coordination of a substrate to a chiral transition-metal catalyst can be used to enable highly stereoselective nucleophilic attack on intermediate tertiary carbocations. This approach has been implemented to achieve the first example of enantioselective reductive deoxygenation of tertiary alcohols. This reduction occurs with high enantio- (up to 96% ee) and regioselectivity (up to >50:1 rr) by applying a novel Hantzsch ester analogue as a convenient hydride source. In-depth mechanistic studies support the involvement of a tertiary carbocation that is coordinated to the iridium metal center via the key allene moiety.
Cycloisomerization of Conjugated Allenones into Furans under Mild Conditions Catalyzed by Ligandless Au Nanoparticles
Zorba, Leandros,Kidonakis, Marios,Saridakis, Iakovos,Stratakis, Manolis
supporting information, p. 5552 - 5555 (2019/08/01)
Au nanoparticles supported on TiO2 (1 mol %) catalyze the quantitative cycloisomerization of conjugated allenones into furans under very mild conditions. The reaction rate is accelerated by adding acetic acid (1 equiv), but the acid does not participate in the protodeauration step as in the corresponding Au(III)-catalyzed transformation. The process is purely heterogeneous, allowing thus the recycling and reuse of the catalyst effectively in several runs.
Zinc Amide Catalyzed Regioselective Allenylation and Propargylation of Ketones with Allenyl Boronate
Yamashita, Yasuhiro,Cui, Yi,Xie, Peizhong,Kobayashi, Shu
supporting information, p. 6042 - 6045 (2016/01/09)
Zinc amide catalyzed, regioselective allenylation and propargylation of ketones with allenyl boronate is reported. Tertiary allenyl and homopropargyl alcohols were obtained, respectively, in high selectivities, from the same starting materials, simply by changing the reaction conditions. The substrate scope was wide. Mechanistic studies suggest that the reactions are controlled under kinetic and thermodynamic conditions.
Carbon-Carbon Bond-Forming Reactions Using Cerium Metal or Organocerium(III) Reagents
Imamoto, Tsuneo,Kusumoto, Tetsuo,Tawarayama, Yoshinori,Sugiura, Yasushi,Mita, Takeshi,et al.
, p. 3904 - 3912 (2007/10/02)
Carbon-carbon bond-forming reactions using cerium metal or organocerium(III) reagents have been investigated.Cerium amalgam is an effective reagent for the chemoselective preparation of homoallylic alcohols from allyl halides and carbonyl compounds.These same reagent can also be satisfactorily employed for the Reformatsky-type reaction of α-halo esters with carbonyl compounds.It has been shown that organocerium(III) reagents are conveniently generated by the reaction of organolithiums with cerium(III)iodide or cerium(III)chloride.The reagents are less basic thanorganolithiums or Grignard reagents, and they react cleanly at -78 to -65 deg C with various carbonyl compounds to afford the addition products in high yields, even though the substrates are susceptible to enolization or metal-halogen exchange with simple organolithiums.The same reagents react also with α,β-unsaturated compounds to yield 1,2-addition products in high selectivity.
Anti-inflammatory 1-phenyl-2,3-butadien-1-ols, methods of use and compositions containing same
-
, (2008/06/13)
Disclosed are compounds of the class 1-phenyl-2,3-butadien-1-ol e.g. 2-(p-biphenyl)-3,4-pentadien-2-ol, which are useful by reason of their pharmacological activity in animals, e.g., as anti-inflammatory agents and tranquilizers. Said compounds can be pre
