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.
The first example of formylation of allylzinc reagents using S-phenyl thioformate is presented. The reaction proceeded undermildconditions without any transition-metal catalyst, forming quaternarycarboncenters with reactive functionalities, such as formyl and vinyl groups. Moreover, Barbier-type formylation of an allylic bromide with a sterically demanding thioformate was achieved. As a preliminary
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.