84107-76-6Relevant articles and documents
Bismuth mediated barbier synthesis of α-homoallylic alcohols via a sigmatropic rearrangement in [bmim][HSO4]
Chatterjee, Sucheta,Dey, Papiya,Kanojia, Seema V.,Chattopadhyay, Subrata,Goswami, Dibakar
supporting information, p. 765 - 775 (2020/12/13)
A novel protocol for the Bismuth metal mediated regioselctive crotylation of aldehydes yielding α-homoallylic alcohols has been developed using 20mol% [bmim][HSO4] as a metal activator, as well as a mediator for regioconversion from the initially formed γ-regiomer. The present protocol minimizes the use of conventional solvents and proceeds with good yields and excellent regioselectivities.
Catalytic Nucleophilic Allylation Driven by the Water-Gas Shift Reaction
Denmark, Scott E.,Matesich, Zachery D.,Nguyen, Son T.,Milicevic Sephton, Selena
supporting information, p. 23 - 48 (2018/02/19)
The ruthenium-catalyzed allylation of aldehydes with allylic pro-nucleophiles has been demonstrated to be an efficient means to form carbon-carbon bonds under mild conditions. The evolution of this reaction from the initial serendipitous discovery to its general synthetic scope is detailed, highlighting the roles of water, CO, and amine in the generation of a more complete catalytic cycle. The use of unsymmetrical allylic pro-nucleophiles was shown to give preferential product formation through the modulation of reaction conditions. Both (E)-cinnamyl acetate and vinyl oxirane were efficiently used to form the anti-branched products (up to >20:1 anti/syn) and E-linear products (up to >20:1 E/Z) in high selectivity with aromatic, α,β-unsaturated, and aliphatic aldehydes, respectively. Attempts to render the reaction enantioselective are highlighted and include enantioenrichment of up to 75:25 for benzaldehyde.
Ni-Catalyzed regio- and stereoselective addition of arylboronic acids to terminal alkynes with a directing group tether
Hari Babu, Madala,Ranjith Kumar, Gadi,Kant, Ruchir,Sridhar Reddy, Maddi
, p. 3894 - 3897 (2017/04/04)
Addition of arylboronic acids to directing group tethered acetylenes in a regio and stereoselective manner using an inexpensive catalytic system is achieved for the first time to access highly sought after allyl/homoallyl alcohol/amine units. The apparent vinylnickel intermediate was successfully trapped by the Michael electrophiles to get defined tri- and tetra-substituted olefins. An interesting selectivity switch was observed with internal alkynes.
Zinc-mediated α-regioselective Barbier-type cinnamylation reactions of aldehydes, ketones and esters
Zhao, Li-Ming,Gao, Hua-Shuai,Li, De-Feng,Dong, Jing,Sang, Lan-Lin,Ji, Jie
, p. 4359 - 4366 (2017/07/10)
We report a simple, efficient, and general method for the zinc-mediated regioselective cinnamylation of aldehydes and ketones under Barbier-type conditions in a one-pot synthesis affording the corresponding α-cinnamylated alcohols in moderate to excellent yields. Compared to the literature procedures, this approach is operationally simple, uses simple reactants, and provides direct access to linear α-cinnamylated alcohols with excellent regioselectivity. Experimental results suggest that the reactions proceed through the radical pathway. In addition, the reaction was found to be scalable to the gram-scale and the one-pot protocol is also applicable to less reactive esters leading to bishomoallylic alcohols which were valuable intermediates for desymmetrizing intramolecular Heck cyclization, allowing for the elaboration to functionalized building blocks.
Hot water-promoted cyclopropylcarbinyl rearrangement facilitates construction of homoallylic alcohols
Li, Pei-Fang,Yi, Cheng-Bo,Qu, Jin
, p. 5012 - 5021 (2015/05/05)
In refluxing 9 : 1 (v/v) H2O-1,4-dioxane and without an additional catalyst, the rearrangements of various types of cyclopropyl carbinols were attempted. It was found that the reactions generally gave homoallylic alcohols in good to very high chemical yields. Rearrangements of bicyclic or tricyclic cyclopropyl carbinols readily gave the desired ring-expanded cyclic homoallylic alcohols which are difficult to synthesize by other means.
Regioselective hydrations of 1-aryl-3-en-1-ynes using gold and platinum catalysts: Selective production of 2-en-1-ones and 3-en-1-ones
Mokar, Bhanudas Dattatray,Liu, Rai-Shung
supporting information, p. 8966 - 8969 (2014/08/05)
Regiocontrolled hydrations of 1-aryl-3-en-1-ynes have been accomplished with IPrAuOTf and PtCl2/CO to yield 3-en-1-ones and 2-en-1-ones efficiently; our experimental data indicates that the sizes of catalysts play an important role. This journa
Direct, catalytic monofluorination of sp3 c-h bonds: A radical-based mechanism with ionic selectivity
Pitts, Cody Ross,Bloom, Steven,Woltornist, Ryan,Auvenshine, Dillon Jay,Ryzhkov, Lev R.,Siegler, Maxime A.,Lectka, Thomas
supporting information, p. 9780 - 9791 (2014/07/22)
Recently, our group unveiled a system in which an unusual interplay between copper(I) and Selectfluor effects mild, catalytic sp3 C-H fluorination. Herein, we report a detailed reaction mechanism based on exhaustive EPR, 19F NMR, UV-vis, electrochemical, kinetic, synthetic, and computational studies that, to our surprise, was revealed to be a radical chain mechanism in which copper acts as an initiator. Furthermore, we offer an explanation for the notable but curious preference for monofluorination by ascribing an ionic character to the transition state.
Operationally simple and highly (E)-styrenyl-selective heck reactions of electronically nonbiased olefins
Werner, Erik W.,Sigman, Matthew S.
supporting information; experimental part, p. 9692 - 9695 (2011/08/06)
Simple, mild, and efficient conditions are reported for a Pd 0-catalyzed Heck reaction that delivers high yields and selectivity for (E)-styrenyl products using electronically nonbiased olefin substrates bearing a range of useful functionality. Preliminary mechanistic studies demonstrate that the σ-donating DMA solvent is crucial for high selectivity. Further studies suggest that the catalyst distinguishes between β-hydrogens on the basis of their relative hydridic character, in contrast to previously reported PdII-catalyzed oxidative reaction conditions.
Titanium-mediated oxidative arylation of homoallylic alcohols
Lee, Kathleen S.,Ready, Joseph M.
supporting information; experimental part, p. 2111 - 2114 (2011/04/23)
E-Substituted styrene derivatives are synthesized from terminal olefins and aryl Grignard reagents through TiIV-mediated oxidative coupling (see scheme). Substrates include homoallylic alcohols containing a range of functional groups and substituted aryl Grignard reagents. The reaction may proceed through aryltitanation followed by β-hydride elimination; reductive elimination of arene occurs from a TiIVH(aryl) intermediate.
A highly selective and general palladium catalyst for the oxidative heck reaction of electronically nonbiased olefins
Werner, Erik W.,Sigman, Matthew S.
supporting information; experimental part, p. 13981 - 13983 (2010/12/24)
A general, highly selective oxidative Heck reaction is reported. The reaction is high-yielding under mild conditions without the need for base or high temperatures, and the selectivity is excellent, without the requirement for electronically biased olefins or other specific directing groups. A preliminary mechanistic investigation suggests that the unusually high selectivity may be due to the catalyst's sensitivity to C-H bond strength in the selectivity-determining β-hydride elimination step.
