68844-05-3Relevant academic research and scientific papers
Chiral Synthesis of 3-Substituted and 3,3-Disubstituted γ-Butyrolactones by Enantioselective Deprotonation Strategy
Honda, Toshio,Kimura, Nobuaki,Tsubuki, Masayoshi
, p. 1475 - 1478 (1993)
Chiral synthesis of 3-substituted and 3,3-disubstituted γ-butyrolactones was achieved by employing an enantioselctive deprotonation of the corresponding cyclobutanone derivatives with chiral bases as a key reaction.
Enantioselective Rh-Catalyzed Anti-Markovnikov Hydroformylation of 1,1-Disubstituted Allylic Alcohols and Amines: An Efficient Route to Chiral Lactones and Lactams
You, Cai,Li, Shuailong,Li, Xiuxiu,Lv, Hui,Zhang, Xumu
, p. 8529 - 8533 (2019)
Rh-catalyzed highly enantioselective anti-Markovnikov hydroformylation of 1,1-disubstituted allylic alcohols and amines has been achieved. By using a chiral hybrid phosphorus ligand, a series of challenging 1,1-disubstituted allylic alcohols and amines we
The rationale for stereoinduction in conjugate addition to alkylidenemalonates bearing a menthol-derived chiral auxiliary
Yamada, Ken-ichi,Fujiwara, Shinichi,Inokuma, Tsubasa,Sugano, Masayuki,Yamaoka, Yousuke,Takasu, Kiyosei
, (2021/06/16)
Density-functional theory (DFT) calculations provided a new model to rationalize the stereoselectivity in the asymmetric addition to alkylidenemalonate bearing 8-phenylmenthyl groups as a chiral auxiliary. The diastereoselectivity in the addition reactions of a tetramethyldioxolanyl radical with various alkyl 8-phenylmenthyl benzylidenemalonates strongly supports the proposed model.
Asymmetric Conjugate Addition of Chiral Secondary Borylalkyl Copper Species
Jang, Won Jun,Woo, Jeongkyu,Yun, Jaesook
supporting information, p. 4614 - 4618 (2021/01/18)
We report the diastereo- and enantioselective conjugate addition of chiral secondary borylalkyl copper species derived from borylalkenes in situ to α,β-unsaturated diesters. In the presence of a chiral bisphosphine-ligated CuH catalyst, the conjugate addition provides a direct access to enantioenriched alkylboron compounds containing two contiguous carbon stereogenic centers in good yield with high diastereo- and enantioselectivity (up to >98:2 dr, >99:1 er) by assembling readily available starting alkenyl reagents in a single operation without using preformed organometallic reagents or chiral auxiliaries. The resulting products were used in various organic transformations. The utility of the synthetic approach was highlighted by the synthesis of (?)-phaseolinic acid.
Investigation of a New Type I Baeyer–Villiger Monooxygenase from Amycolatopsis thermoflava Revealed High Thermodynamic but Limited Kinetic Stability
Mansouri, Hamid R.,Mihovilovic, Marko D.,Rudroff, Florian
, p. 971 - 977 (2020/01/22)
Baeyer–Villiger monooxygenases (BVMOs) are remarkable biocatalysts, but, due to their low stability, their application in industry is hampered. Thus, there is a high demand to expand on the diversity and increase the stability of this class of enzyme. Sta
The mutagenesis of a single site for enhancing or reversing the enantio- or regiopreference of cyclohexanone monooxygenases
Hu, Yujing,Xu, Weihua,Hui, Chenggong,Xu, Jian,Huang, Meilan,Lin, Xianfu,Wu, Qi
supporting information, p. 9356 - 9359 (2020/11/02)
The mutagenesis of a "second sphere"switch residue of CHMOAcineto could control its enantio- and regiopreference. Replacing phenylalanine (F) at position 277 of CHMOAcineto into larger tryptophan (W) enabled a significant enhancement of enantio- or regioselectivity toward structurally diverse substrates, moreover, a complete reversal of enantio- or regiopreference was realized by mutating F277 into a range of smaller amino acids (A/C/D/E/G/H/I/K/L/M/N/P/Q/R/S/T/V).
Phosphothreonine (pThr)-Based Multifunctional Peptide Catalysis for Asymmetric Baeyer-Villiger Oxidations of Cyclobutanones
Featherston, Aaron L.,Shugrue, Christopher R.,Mercado, Brandon Q.,Miller, Scott J.
, p. 242 - 252 (2019/01/04)
Biologically inspired phosphothreonine (pThr)-embedded peptides that function as chiral Br?nsted acid catalysts for enantioselective Baeyer-Villiger oxidations (BV) of cyclobutanones with aqueous H2O2 are reported herein. Complementa
Heterogeneous Chiral Diene-Rh Complexes for Asymmetric Arylation of α,β-Unsaturated Carbonyl Compounds, Nitroalkenes, and Imines
Kuremoto, Tatsuya,Yasukawa, Tomohiro,Kobayashi, Shū
supporting information, p. 3698 - 3703 (2019/07/12)
A chiral diene ligand with tertiary alkyl amine-derived secondary amide moiety was immobilized on cross-linked polystyrene (PS) by radical polymerization, which was combined with Rh to form heterogeneous chiral Rh complexes (PS-diene Rh?Cl). PS-diene Rh?Cl catalyzed asymmetric arylation reactions of α,β-unsaturated carbonyl compounds (ketones, esters, and amides), nitroalkenes, and imines afforded the desired products in high yields with excellent enantioselectivities. PS-diene Rh?Cl is stable in air, can be stored for several months, and can be reused more than 10 times without any reduction of either yield or enantioselectivity. We also developed a method of activation of PS-diene Rh?Cl to generate more active species. (Figure presented.).
Catalytic Asymmetric Conjugate Addition of a Borylalkyl Copper Complex for Chiral Organoboronate Synthesis
Jang, Won Jun,Yun, Jaesook
supporting information, p. 18131 - 18135 (2019/11/13)
We report the catalytic enantioselective conjugate addition of a borylalkyl copper nucleophile generated in situ from a 1,1-diborylmethane derivative to α,β-unsaturated diesters. In the presence of a chiral N-heterocyclic carbene (NHC)–copper catalyst, this method facilitated the enantioselective incorporation of a CH2Bpin moiety at the β-position of the diesters to yield β-chiral alkyl boronates in up to 86 % yield with high enantioselectivity. The alkylboron moiety in the resulting chiral diester products was converted into various functional groups by organic transformation of the C?B bond.
A diastereomeric pair of sulfoxide-containing chiral MOP-type ligands: Preparation and application to rhodium-catalyzed asymmetric 1,4-addition reactions
Hoshi, Takashi,Fujita, Masataka,Matsushima, Shouta,Hagiwara, Hisahiro,Suzuki, Toshio
supporting information, p. 800 - 802 (2018/06/12)
(R,SS)-Sulfoxide-MOP (L2) and (R,RS)-sulfoxide-MOP (L3) were developed as a diastereomeric pair of sulfoxide-containing chiral MOP-type ligands. These two ligands also represent the first monosulfoxide analogues of BINAP. The chiral ligand L2 was successfully applied to the highly enantioselective rhodium-catalyzed 1,4-addition between α,β-unsaturated ketones or esters and arylboronic acids, and exhibited a broad substrate scope when the reaction was performed using 1.5 mol% Rh in cyclohexane/H2O (10:1) at 40 °C under mild basic conditions.
