Synergistic <i>N</i>-Heterocyclic Carbene/Palladium-Catalyzed [3 + 2] Annulation of Vinyl Enolates with 1-Tosyl-2-vinylaziridine
作者:Jian Gao、Jianming Zhang、Shuaishuai Fang、Jie Feng、Tao Lu、Ding Du
DOI:10.1021/acs.orglett.0c02935
日期:2020.10.2
(E)-3-ethylidene-4-vinylpyrrolidin-2-ones in a regioselective and stereoselective manner. The preliminary asymmetric studies were also performed, which indicated a potential for enantioselective annulation of vinyl enolate intermediates with transition-metal−π-allyl species.
Carbene-catalyzed enal γ-carbon addition to α-ketophosphonates for enantioselective access to bioactive 2-pyranylphosphonates
作者:Jun Sun、Fangcheng He、Zhongyao Wang、Dingwu Pan、Pengcheng Zheng、Chengli Mou、Zhichao Jin、Yonggui Robin Chi
DOI:10.1039/c8cc03017k
日期:——
A carbene-catalyzed enantioselective [4+2] cycloaddition reaction between α,β-unsaturated aldehydes and α-ketophosphonates is developed. The reaction affords chiral 2-pyranylphosphonates with excellent enantioselectivities. The optically enriched phosphonate products bear multiple functional groups, including unsaturated lactone and phosphonate moieties that often lead to unique bio-activities. Preliminary
Catalytic Asymmetric Transfer Hydrogenation of <i>trans</i>-Chalcone Derivatives Using BINOL-derived Boro-phosphates
作者:Fei Na、Susana S. Lopez、Alice Beauseigneur、Lucas W. Hernandez、Zhuoxin Sun、Jon C. Antilla
DOI:10.1021/acs.orglett.0c02042
日期:2020.8.7
Chiral phosphoric-acid-catalyzed asymmetric reductions of trans-chalcones have been investigated in this work. A BINOL-derived boro-phosphate-catalyzed asymmetric transfer hydrogenation of the carbon–carbon double bond of trans-chalcone derivatives employing borane as a hydride source was realized. This methodology provides a convenient procedure to accesschiral dihydrochalone derivatives in high
Metal-Free Domino One-Pot Decarboxylative Cyclization of Cinnamic Acid Esters: Synthesis of Functionalized Indanes
作者:Alavala Gopi Krishna Reddy、Gedu Satyanarayana
DOI:10.1021/acs.joc.6b02015
日期:2016.12.16
Their formation can be explained via acid triggered decarboxylation of cinnamic acid esters and subsequent inter/intramolecular cyclization. Overall process involves in the intramolecular cleavage of two σ-bonds (C–O and C–C) and inter/intramolecular construction of two/one C–C σ-bond(s). Significantly, this protocol was successful without the aid of any metal salts.
Ir‐phosphinomethyl‐oxazoline complexes have been identified as efficient, highlyenantioselective catalysts for the asymmetric hydrogenation of 3,3‐disubstituted allylicalcohols and related homoallylic alcohols. In contrast to other N,Pligand complexes, which require weakly coordinating solvents, such as dichloromethane, these catalysts perform well in more ecofriendly THF or 2‐MeTHF. Their synthetic