on the control of diastereoselectivity by H-bond donors. While the squaramide-catalyzed reaction proceeded with a transition state with both squaramide N–H bonds binding to an enolate intermediate, an unprecedented model was proposed for the phosphoramide-mediated reaction wherein an amide N–H bond and an alkylammonium ion formed in situ interact with nitroolefins, with the enolate stabilized by nonclassical
Facile One‐Step Conversion of Ketones into α‐Azidoketones using [Hydroxy(tosyloxy)iodo]benzene and Sodium Azide in the Presence of a Phase‐Transfer Catalyst under Solvent‐Free Conditions
作者:Dalip Kumar、Swapna Sundaree、V. S. Rao
DOI:10.1080/00397910600602644
日期:2006.7
iodo]‐benzene reagent, sodium azide, and phase‐transfercatalyst at room temperature. Generality of the protocol has been demonstrated by synthesizing various α‐azidoketones high in yield and purity within a short time. The work entitled “A Facile One‐Step Conversion of Ketones into α‐Azidoketones Using [Hydroxy(tosyloxy)iodo]benzene and Sodium Azide in Presence of PhaseTransferCatalyst Under Solvent‐Free
摘要 我们描述了从相应的酮中一步无溶剂合成 α-叠氮酮,该合成需要相对温和的 [羟基(甲苯磺酰氧基)碘]-苯试剂、叠氮化钠和室温下的相转移催化剂。通过在短时间内合成各种高产率和纯度的 α-叠氮酮,证明了该协议的通用性。题为“A Facile One-Step Conversion of Ketones into α-Azidoketones Using [Hydroxy(tosyloxy)iodo]benzo and钠在无溶剂条件下存在相转移催化剂”的工作尚未在其他地方发表,也没有同时提交在别处出版。
Domino ‘Staudinger–aza-Wittig–1,5-phosphonium-rearrangement–fragmentation’ reactions of 1-azido-2-hydroxy-4,6-dioxohexanes
作者:Peter Langer、Ilia Freifeld、Heydar Shojaei
DOI:10.1039/b310701a
日期:——
The domino âStaudingerâaza-Wittigâ1,5-phosphonium-rearrangementâfragmentationâ reaction of 1-azido-2-hydroxy-4,6-dioxohexanes allows a convenient synthesis of functionalized 1-acetamido-2-alkylidenecyclopentanes.
Synthesis of 2-Alkylidenepyrrolidines and Pyrroles by Condensation of 1,3-Dicarbonyl Dianions with α-Azidoketones and Subsequent Intramolecular Staudinger−Aza-Wittig Reaction
作者:Ilia Freifeld、Heydar Shojaei、Peter Langer
DOI:10.1021/jo060593h
日期:2006.6.1
The condensation of 1,3-dicarbonyl dianions with α-azidoketones afforded open-chained condensation products that were transformed into pyrroles by Staudinger−aza-Wittig reactions and the subsequent treatment with trifluoroacetic acid.
Direct enantioselective Mannich reactions of α-azido cyclic ketones: asymmetric construction of chiral azides possessing an α-quaternary stereocenter
作者:Xueqian Ye、Yongkai Pan、Xiaoyu Yang
DOI:10.1039/c9cc08000g
日期:——
Direct enantioselective Mannich reactions of α-azido cyclicketones with aldimines are realized through chiral phosphoric acid catalysis, which generate chiral azides possessing an α-quanternary stereocenter with complete regioselectivities and high diastereoselectivities and enantioselectivities.