24844-28-8Relevant academic research and scientific papers
NHC-Ni(0) Catalyzed Diastereodivergent Hydroacylative Enyne Cyclization: Synthesis of Heterocycles bearing γ-Enone
Yong, Xuefeng,Ng, Elvis Wang Hei,Zhen, Zibo,Lin, Xiulian,Gao, Weiwei,Ho, Chun-Yu
supporting information, p. 4164 - 4172 (2020/08/26)
NHC-Nickel(0) catalyzed 1,3- and 1,4-diastereodivergent hydroacylative heteroenyne cyclization with aldehydes was achieved (Syn-:Anti-, switchable from up to 1:99 to 98:2). Both sets of heterocyclic diastereomers are accessible via this route, with a high
Direct Asymmetric Hydrogenation and Dynamic Kinetic Resolution of Aryl Ketones Catalyzed by an Iridium-NHC Exhibiting High Enantio- and Diastereoselectivity
Ayya Swamy P, Chinna,Varenikov, Andrii,de Ruiter, Graham
supporting information, p. 2333 - 2337 (2020/02/11)
A chiral iridium carbene-oxazoline catalyst is reported that is able to directly and efficiently hydrogenate a wide variety of ketones in excellent yields and good enantioselectivity (up to 93 % ee). Moreover, when using racemic α-substituted ketones, excellent diastereoselectivities were obtained (dr 99:1) by dynamic kinetic resolution of the in situ formed enolate. Overall, the herein described hydrogenation occurs under ambient conditions using low hydrogen pressures, providing a direct and atom efficient method towards chiral secondary alcohols.
Chiral Imidazo[1,5- a]pyridine-Oxazolines: A Versatile Family of NHC Ligands for the Highly Enantioselective Hydrosilylation of Ketones
Chinna Ayya Swamy,Varenikov, Andrii,Ruiter, Graham De
supporting information, p. 247 - 257 (2020/02/04)
Herein we report the synthesis and application of a versatile class of N-heterocyclic carbene ligands based on an imidazo[1,5-a]pyridine-3-ylidine backbone that is fused to a chiral oxazoline auxiliary. The key step in the synthesis of these ligands involves the installation of the oxazoline functionality via a microwave-assisted condensation of a cyano-azolium salt with a wide variety of 2-amino alcohols. The resulting chiral bidentate NHC-oxazoline ligands form stable complexes with rhodium(I) that are efficient catalysts for the enantioselective hydrosilylation of structurally diverse ketones. The corresponding secondary alcohols are isolated in good yields (typically >90%) with good to excellent enantioselectivities (80-93% ee). The reported hydrosilylation occurs at ambient temperatures (40 °C), with excellent functional group tolerability. Even ketones bearing heterocyclic substituents (e.g., pyridine or thiophene) or complex organic architectures are hydrosilylated efficiently, which is discussed further in this report.
Cobalt-Catalyzed Stereoselective Synthesis of 2,5- trans-THF Nitrile Derivatives as a Platform for Diversification: Development and Mechanistic Studies
Ali, Sajjad,Milanezi, Henrique,Alves, Tania M. F.,Tormena, Cláudio Francisco,Ferreira, Marco A. B.
, p. 7694 - 7713 (2018/06/18)
A straightforward protocol integrating a sustainable approach for the synthesis of new 2,5-trans-THF nitrile derivatives enabling an easy diversification of its side chain scaffolds is described. The reaction tolerated different aromatic and alkyl substit
I2-Mediated oxidative bicyclization of 4-pentenamines to prolinol carbamates with CO2 incorporating oxyamination of the C=C bond
Wang, Sheng,Zhang, Xiaowei,Cao, Chengyao,Chen, Chao,Xi, Chanjuan
supporting information, p. 4515 - 4519 (2017/10/13)
A metal-free oxyamination reaction of alkenes with ambient CO2 is reported. In the presence of I2 and DBU, CO2 is applied in situ as a protecting group to regulate the nucleophilicity of the amino group and facilitate the bicyclization of 4-pentenamines with high chemoselectivity. Moreover, this reaction provided a feasible approach to prepare prolinol carbamates with good tolerance of functional groups and high efficiency under mild conditions.
COMPOUNDS THAT INHIBIT MCL-1 PROTEIN
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Page/Page column 930, (2017/09/15)
Provided herein are myeloid cell leukemia 1 protein (Mcl-1) inhibitors, methods of their preparation, related pharmaceutical compositions, and methods of using the same. For example, provided herein are compounds of Formula I, and pharmaceutically acceptable salts thereof and pharmaceutical compositions containing the compounds. The compounds and compositions provided herein may be used, for example, in the treatment of diseases or conditions, such as cancer.
Acceleration of acetal hydrolysis by remote alkoxy groups: Evidence for electrostatic effects on the formation of oxocarbenium ions
Garcia, Angie,Otte, Douglas A. L.,Sanzone, Jillian R.,Woerpel, K. A.,Salamant, Walter A.
supporting information, p. 3061 - 3064 (2015/05/05)
In contrast to observations with carbohydrates, experiments with 4-alkoxy-substituted acetals indicate that an alkoxy group can accelerate acetal hydrolysis by up to 20-fold compared to substrates without an alkoxy group. The acceleration of ionization in more flexible acetals can be up to 200-fold when compensated for inductive effects.
Intramolecular palladium-catalyzed alkene carboalkynylation
Nicolai, Stefano,Swallow, Peter,Waser, Jerome
supporting information, p. 5959 - 5964 (2015/08/03)
Abstract Carbocycles are essential building blocks for the synthesis of natural and synthetic bioactive compounds. Herein, we report the first example of palladium-catalyzed intramolecular carboalkynylation of non-activated olefins. Using activated carbon
Annulated and bridged tetrahydrofurans from alkenoxyl radical cyclization
Schur, Christine,Kelm, Harald,Gottwald, Thomas,Ludwig, Arne,Kneuer, Rainer,Hartung, Jens
, p. 8288 - 8307 (2015/01/09)
4-Pentenoxyl radicals sharing two or more carbon atoms with a cycloalkane cyclize in a predictable manner stereoselectively and regioselectively to afford in solutions of bromotrichloromethane cycloalkyl-fused or -bridged 2-bromomethyltetrahydrofurans in up to 95% yield. Stereoselectivity in alkenoxyl radical ring closures arises from cumulative steric effects. The substituent positioned the closest to the alkene carbon, which is being attacked by the oxygen radical, exerts the strongest stereodirecting effect. This principal inductor guides 5-exo-cyclization 2,3-trans- or 2,4-cis-selectively. The substituent located further from the attacked π-bond is the secondary inductor. A secondary inductor in the relative trans-configuration enhances stereodifferentiation by the primary inductor; a cis-configured secondary inductor decreases this effect. A secondary inductor is not able to overrule the guiding effect of a similar sized primary inductor. Intramolecular 4-pentenoxyl radical additions to a cyclohexene-bound exo-methylene group or to endocyclic double bonds proceed cis-specifically, as exemplified by synthesis of a diastereomerically pure bromobicyclo[2.2.1]heptyl-annulated tetrahydrofuran from the verbenylethyloxyl radical. According to theory, the experimental 2,3-cis-specificity in alkoxyl radical cyclization to an endocyclic π-bond arises from strain associated with the 2,3-trans-ring closure. This journal is
Catalytic hydrogenation of aromatic rings catalyzed by Pd/NiO
Wang, Yanan,Cui, Xinjiang,Deng, Youquan,Shi, Feng
, p. 2729 - 2732 (2014/01/06)
A simple and efficient heterogeneous palladium catalyst was prepared for aromatic ring hydrogenation. The catalyst was prepared by a reduction-deposition method and exhibited high activity and selectivity for the hydrogenation of a variety of substituted aromatic compounds to the corresponding cyclohexane and cyclohexanol derivatives with up to 99% yields. The catalyst was characterized by BET, TEM, XRD, XPS and ICP. Meanwhile the reusability of the catalyst was investigated, and it can be reused for several runs without significant deactivation.
