20498-05-9Relevant academic research and scientific papers
1,4-Conjugate addition of allyltrimethylsilane to α,β-unsaturated ketones
Yadav,Reddy,Sadasiv,Satheesh
, p. 9695 - 9697 (2002)
α,β-Unsaturated ketones smoothly undergo conjugate addition with allyltrimethylsilane in the presence of a catalytic amount of elemental iodine under very mild and convenient conditions to afford the corresponding Michael adducts in high yields with high
Visible-Light Controlled Divergent Catalysis Using a Bench-Stable Cobalt(I) Hydride Complex
Beltran, Frédéric,Bergamaschi, Enrico,Teskey, Christopher J.
supporting information, p. 5180 - 5184 (2020/04/22)
While the use of visible light in conjunction with transition metal catalysis offers powerful opportunities to switch between on/-off states of catalytic activity, the next frontier would be the ability to switch the actual function of the catalyst and resulting products. Here we report such an example of multi-dimensional catalysis. Featuring an easily prepared, bench-stable cobalt(I) hydride complex in conjunction with pinacolborane, we can switch the reaction outcome between two widely employed transformations, olefin migration and hydroboration, with visible light as the trigger.
First synthesis of α,β-unsaturated lactones with high diversity through the Passerini reaction and ring-closing metathesis (RCM)
Schwaeblein, Almuth,Martens, Juergen
experimental part, p. 4335 - 4344 (2011/09/15)
A new class of α,β-unsaturated pyran-2-carboxamides was easily accessed by a multicomponent reaction (MCR), followed by a ring-closing metathesis (RCM) using a ruthenium catalyst. In the first step, α-acyloxy carboxamides with two terminal double bonds were formed from terminal unsaturated carboxylic acids, allyl ketones, and isocyanides (Passerini reaction, P-3CR). A new class of α,β-unsaturated pyran-2-carboxamides was easily accessed by amulticomponent reaction (MCR), followedby a ring-closing metathesis (RCM) using a ruthenium catalyst.
Formation of carbocycles by intramolecular conjugate displacement: Scopeand mechanistic insights
Wang, Lihong,Prabhudas, Bodhuri,Clive, Derrick L. J.
supporting information; experimental part, p. 6003 - 6012 (2009/09/25)
A detailed study has been made of a method of ring closure categorized as an all-carbon intramolecular conjugate displacement (ICD). This reaction involves intramolecular addition of a carbanion, which is stabilized by at least one electron-withdrawing group, to a Michael acceptor which has a leaving group in an allylic position. The process formally resembles a combination of Michael addition and S N2' displacement. The overall result is formation of a ring with loss of the allylic leaving group and shift of the original double bond to a new location spanning the positions of the electron-withdrawing substituent of the Michael acceptor subunit and the original allylic leaving group. The starting materials are easily prepared by a selenium-based version of the Morita-Baylis-Hillman reaction. The cyclizations are transition metal free and occur under mild conditions, using DBU or Cs 2CO 3 inMeCN or THF. Acetate is a suitable leaving group and the electron-withd rawing substituent of the Michael acceptor unit can be CO 2R,SO 2Ph, or CN. Six- and seven-membered rings are formed effi ciently, and complex structures, such as those resembling the core of CP-225,917, are easily assembled. The products of these ICD reactions are themselves classical Michael acceptors. A range of mechanisms probably operates, depending on the structure of the starting material and the reaction conditions, but conclusive evidence for a stepwise mechanism was obtained in a suitably biased case, while other observations are compatible with a concerted process or a stepwise path involving a short-lived carbanion that evades capture by a proton source.
Catalytic enantioselective Hosomi-Sakurai conjugate allylation of cyclic unsaturated ketoesters
Shizuka, Manami,Snapper, Marc L.
supporting information; experimental part, p. 5049 - 5051 (2009/03/11)
(Chemical Equation Presented) No fancy catalyst required: The copper-catalyzed enantioselective conjugate allylation of activated cyclic enones affords products in up to >98% ee. Reactions proceed to high conversion in the presence of commercially availab
Cascade radical carbonylations leading to 3-substituted cyclohexanones
Uenoyama, Yoshitaka,Fukuyama, Takahide,Ryu, Ilhyong
, p. 2342 - 2344 (2007/10/03)
Tin radical mediated [5+1]-annulation methods leading to 3-substituted cyclohexanones were investigated. Cyclohexanones having a quaternary center at the 3-position were synthesized in good yields by allyltin-mediated three- and four-component cascade rea
Efficient Addition of Allylsilanes to α,β-Enones Using Catalytic Indium and Trimethylsilyl Chloride
Lee, Phil Ho,Seomoon, Dong,Kim, Sundae,Nagaiah,Damle,Lee, Kooyeon
, p. 2189 - 2193 (2007/10/03)
α,β-Enones undergo an efficient Hosomi-Sakurai reaction with allyltrimethylsilane, in which a catalytic amount of indium is used in the presence of trimethylsilyl chloride as an activator under mild conditions to produce the conjugate addition products in good yields.
Generation of organotantalum reagents and conjugate addition to enones
Shibata, Ikuya,Kano, Takeyoshi,Kanazawa, Nobuaki,Fukuoka, Shoji,Baba, Akio
, p. 1389 - 1392 (2007/10/03)
A superior method of conjugate allylation: The transmetalation of allyltin compounds with TaCl5 yielded active tantalum reagents for conjugate addition to enones. Even bulky allyl moieties could be introduced to enones in this manner (see scheme). Both cyclic and acyclic enones reacted facilely under extremely mild conditions.
Carbon-carbon bond forming reactions by using bistrifluoromethanesulfonimide
Cossy,Lutz,Alauze,Meyer
, p. 45 - 48 (2007/10/03)
Bistrifluoromethanesulfonimide has been used to catalyze C-C bond forming reactions such as Friedel-Crafts, Mukaiyama, 1,2-addition and 1,4-addition as well as C-glycosidation reactions.
