69668-93-5Relevant articles and documents
Relative rates of hydrosilylation of representative alkenes and alkynes by Cp*2YMe·THF and [Cp2sYMe]2
Molander, Gary A.,Knight, Elizabeth E.
, p. 7009 - 7012 (1998)
Reactivity in the hydrosilylation of alkenes and alkynes catalyzed by the organoyttrium catalysts Cp*2YMe·THF and [Cp2SYMe]2 is generally determined by the steric environment of the substrate. Alkynes and conjugated alkenes show an increased reaction rate because of electronic effects; the magnitude of this increase is highly substrate dependent. The electron rich pyrrole system is particularly reactive, especially with the sterically open [Cp2TMSYMe]2 precatalyst. For nonconjugated substrates, Cp*2YMe·THF is generally a more selective catalyst than [Cp2TMSYMe]2.
Expanding Zirconocene Hydride Catalysis: In Situ Generation and Turnover of ZrH Catalysts Enabling Catalytic Carbonyl Reductions
Kehner, Rebecca A.,Hewitt, Matthew Christian,Bayeh-Romero, Liela
, p. 1758 - 1763 (2022/02/07)
Despite the wide use and popularity of metal hydride catalysis, methods utilizing zirconium hydride catalysts remain underexplored. Here, we report the development of a mild method for the in situ preparation and use of zirconium hydride catalysts. This r
Nickel-Catalyzed Asymmetric Friedel-Crafts Propargylation of 3-Substituted Indoles with Propargylic Carbonates Bearing an Internal Alkyne Group
Miyazaki, Yusuke,Zhou, Biao,Tsuji, Hiroaki,Kawatsura, Motoi
supporting information, p. 2049 - 2053 (2020/03/04)
The nickel-catalyzed highly enantioselective Friedel-Crafts propargylation of 3-substituted indoles with propargylic carbonates bearing an internal alkyne group was developed. A wide array of the propargylic carbonates as well as 3-substituted indoles can be applicable to the asymmetric nickel catalysis, providing the corresponding chiral C-3 propargylated indolenine derivatives bearing two vicinal chiral centers in up to 89% yield with up to >99% ee and 94:6 dr (24 examples).
Catalytic Access to Functionalized Allylic gem-Difluorides via Fluorinative Meyer–Schuster-Like Rearrangement
An, Rui,Li, Huimin,Liao, Lihao,Wu, Jin-Ji,Xu, Yang,Zhao, Xiaodan
supporting information, p. 11010 - 11019 (2020/05/18)
An unprecedented approach for efficient synthesis of functionalized allylic gem-difluorides via catalytic fluorinative Meyer–Schuster-like rearrangement is disclosed. This transformation proceeded with readily accessible propargylic fluorides, and low-cost B–F reagents and electrophilic reagents by sulfide catalysis. A series of iodinated, brominated, and trifluoromethylthiolated allylic gem-difluorides that were difficult to access by other methods were facilely produced with a wide range of functional groups. Importantly, the obtained iodinated products could be incorporated into different drugs and natural products, and could be expediently converted into many other valuable gem-difluoroalkyl molecules as well. Mechanistic studies revealed that this reaction went through a regioselective fluorination of alkynes followed by a formal 1,3-fluorine migration under the assistance of the B–F reagents to give the desired products.
Ruthenium-catalyzed [2 + 2] cycloadditions between norbornene and propargylic alcohols or their derivatives
Tsui, Gavin C.,Villeneuve, Karine,Carlson, Emily,Tam, William
, p. 3847 - 3856 (2014/08/18)
Diastereoselective ruthenium-catalyzed [2 + 2] cycloadditions of norbornene and propargylic alcohols or their derivatives were investigated. The cycloadditions were found to be highly stereoselective, giving exo cycloadducts in moderate to excellent yields with diastereoselectivities up to 92:8. When a chiral propargylic alcohol was used in the cycloaddition, up to 80% ee of the [2 + 2] cycloadducts was observed after oxidation of the alcohol.
Mo-Au combo catalysis for rapid 1,3-rearrangement of propargyl alcohols into α,ss-unsaturated carbonyl compounds
Egi, Masahiro,Yamaguchi, Yoshiko,Fujiwara, Noboru,Akai, Shuji
supporting information; experimental part, p. 1867 - 1870 (2009/04/18)
The combination of Mo and cationic Au catalysts dramatically accelerated the rearrangement of diverse propargyl alcohols, which includes a short reaction time, mild conditions, and high product yields. A practical application to the highly challenging primary propargyl alcohols and the N-alkynyl amides is achieved.
Highly regio- and stereoselective hydrostannylation of alkynols with a new Lewis acidic hydrostannane
Miura, Katsukiyo,Wang, Di,Matsumoto, Yukihiro,Hosomi, Akira
, p. 503 - 505 (2007/10/03)
(Chemical Equation Presented) Bu2Sn(OTf)H (1a), easily prepared from Bu2SnH2 and TfOH, was found to be very valuable for highly regio- and stereoselective hydrostannylation of various propargyl alcohols leading to (Z)-γ-st
Alkyliron and Alkylcobalt Reagents, IV.- High Superiority of Me4CoLi2 and Me4FeLi2 in Comparison to Me2CuLi and Me4MnLi2 in Cross Coupling Reactions with Vinyl Bromides
Kauffmann, Thomas,Stach, Dirk
, p. 913 - 922 (2007/10/02)
The complexes Me4MLi2 (M = Co, Fe, Mn) and Me2CuLi (prepared in situ, but well-known in isolated form) were treated with a series of vinyl bromides.In nearly all cases Me4CoLi2 and Me4FeLi2 proved to by far the best methylating reagents (high yields, reaction at -78 deg C, short reaction time, no excess of the reagent necessary.These reagents will tolerate a hydroxy or cyano group in the substrate, whereas the classical reagent for methylation of vinyl bromides, Me2CuLi, is strongly inhibited by these groups.With the methylation of hydroxyvinyl bromides a new method was found for the synthesis of allyl alcohols. Key Words: Organocobalt complexes / Organoiron complexes
