An asymmetric pericyclic cascade approach to 3-alkyl-3-aryloxindoles: generality, applications and mechanistic investigations
作者:Edward Richmond、Kenneth B. Ling、Nicolas Duguet、Lois B. Manton、Nihan Çelebi-Ölçüm、Yu-Hong Lam、Sezen Alsancak、Alexandra M. Z. Slawin、K. N. Houk、Andrew D. Smith
DOI:10.1039/c4ob02526a
日期:——
The reaction of l-serine derived N-arylnitrones with alkylarylketenes generates 3-alkyl-3-aryloxindoles in good yields and excellent enantioselectivities.
Metal‐Free Hydrosilylation of Ketenes with Silicon Electrophiles: Access to Fully Substituted Aldehyde‐Derived Silyl Enol Ethers
作者:Avijit Roy、Martin Oestreich
DOI:10.1002/chem.202100877
日期:2021.6.4
catalysts is reported. The boron Lewis acid tris(pentafluorophenyl)borane accelerates the slow uncatalyzed reaction of ketenes and hydrosilanes, thereby providing a convenient access to the new class of β,β-di- and β-monoaryl-substituted aldehyde-derived silyl enolethers. Yields are moderate to high, and Z configuration is preferred. The corresponding silyl bis-enol ethers are also available when using
N-Heterocyclic Carbene Catalysis: Enantioselective Formal [2+2] Cycloaddition of Ketenes and N-Sulfinylanilines
作者:Teng-Yue Jian、Lin He、Cen Tang、Song Ye
DOI:10.1002/anie.201102488
日期:2011.9.19
Sultam of swing: Both enantiomers of 1,2‐thiazetidin‐3‐one oxides were obtained in very good yields with excellent enantioselectivities when using N‐heterocyclic carbene catalysts (see scheme; M.S.=molecular sieves, TBS=tert‐butyldimethylsilyl). The products were easily converted into 3‐oxo‐β‐sultams, α‐mercapto amides, and β‐mercapto amines through oxidation or reduction.
摇摆的结果:使用N杂环卡宾催化剂时,1,2-噻嗪丁-3-氧化物的两种对映体均以非常高的收率获得,并具有出色的对映选择性(参见方案; MS =分子筛,TBS =叔丁基二甲基甲硅烷基)。产物可以通过氧化或还原轻松地转化为3-氧代-β-杜马酰胺,α-巯基酰胺和β-巯基胺。
Stereo‐ and Chemodivergent NHC‐Promoted Functionalisation of Arylalkylketenes with Chloral
作者:James J. Douglas、Gwydion Churchill、Alexandra M. Z. Slawin、David J. Fox、Andrew D. Smith
DOI:10.1002/chem.201503308
日期:2015.11.9
Stereo‐ and chemodivergent enantioselective reaction pathways are observed upon treatment of alkylarylketenes and trichloroacetaldehyde (chloral) with N‐heterocyclic carbenes, giving selectively either β‐lactones (up to 88:12 dr, up to 94 % ee) or α‐chloroesters (up to 94 % ee). Either 2‐arylsubstitution or an α‐branched iPr alkyl substituent within the ketene favours the chlorination pathway, allowing
Mild Acylation of C(sp<sup>3</sup>)–H and C(sp<sup>2</sup>)–H Bonds under Redox-Neutral Rh(III) Catalysis
作者:Songjie Yu、Yingzi Li、Lingheng Kong、Xukai Zhou、Guodong Tang、Yu Lan、Xingwei Li
DOI:10.1021/acscatal.6b02668
日期:2016.11.4
molecules. Although C–H bond acylation has been well-studied via different mechanisms, transition-metal-catalyzed redox-neutral C(sp3)–H acylation under mild conditions is unprecedented. In this work, ketene is designed as a acylating reagent for both C(sp3)–H and C(sp2)–Hbonds under Rh(III) catalysis, affording a diverse array of carbonyl compounds in high yields and high atom economy under mild conditions