Synthesis of α-Keto-Imides via Oxidation of Ynamides
摘要:
A de novo preparation of alpha-keto-imides via ynamide oxidation is described. With a number of alkyne oxidation conditions screened, a highly efficient RuO2-NaIO4 mediated oxidation and a DMDO oxidation have been identified to tolerate a wide range of ynamide types. In addition to accessing a wide variety of a-keto-imides, the RuO2-NaIO4 protocol provides a novel entry to the vicinal tricarboryl motif via oxidation of push-pull ynamides, and imido acylsilanes from silyl-substituted ynamides. Chemoselective oxidation of ynamides containing olefins can be achieved by using DMDO, while the RuO2-NaIO4 protocol is not effective. These studies provide further support for the synthetic utility of ynamides.
Convenient and Practical Alkynylation of Heteronucleophiles with Copper Acetylides
摘要:
Copper acetylides, readily available reagents which are characterized by their lack of reactivity, can be simply activated by oxidation with oxygen in the presence of simple nitrogen ligands such as TMEDA or imidazole derivatives. Upon activation, these nucleophilic species undergo a formal umpolung and can transfer their alkyne subunit to a wide range of heteronucleophiles, including amides, oxazolidinones, imines, and dialkyl phosphites. This alkynylation, which provides one of the most practical entry to useful building blocks such as ynamides, ynimines, and alkynylphosphonates, proceeds under especially mild conditions and can be easily performed on a multigram scale.
A Green Synthetic Route to Imides from Terminal Alkynes and Amides by Simple Solid Catalysts
作者:Xiongjie Jin、Kazuya Yamaguchi、Noritaka Mizuno
DOI:10.1246/cl.2012.866
日期:2012.9.5
An atom-efficient and green synthetic route to highly valuable imides (54–92% yields) from terminal alkynes and amides has been developed. This new route is composed of two consecutive reactions, that is, (i) the reported Cu(OH)2-catalyzed cross-coupling of terminal alkynes and amides to ynamides and (ii) the Sn–W mixed oxide-catalyzed regioselective hydration of ynamides.
Regiospecific Hydroamination of Unsymmetrical Electron-Rich and Electron-Poor Alkynes with Anilines Catalyzed by Gold(I) Immobilized in MCM-41
作者:Dayi Liu、Quan Nie、Rongli Zhang、Mingzhong Cai
DOI:10.1002/adsc.201800621
日期:2018.10.18
heterogeneous gold(I)‐catalyzedregiospecifichydroamination of ynamides and propiolic acid derivatives with anilines has been achieved by using a diphenylphosphine‐functionalized MCM‐41‐supported gold (I) complex and AgNTf2 as catalysts under mild conditions, yielding the corresponding (E)‐N‐arylimines and (Z)‐enamines in good to excellent yields with broad substrate scope. The new heterogeneous gold(I) complex
Copper-Catalyzed Aerobic Oxidative Amidation of Terminal Alkynes: Efficient Synthesis of Ynamides
作者:Tetsuya Hamada、Xuan Ye、Shannon S. Stahl
DOI:10.1021/ja077406x
日期:2008.1.1
A copper-catalyzed method for the preparation of ynamides has been identified that proceeds via aerobicoxidative coupling of terminal alkynes with various nitrogen nucleophiles, including cyclic carbamates, amides and ureas, and N-alkyl-arylsulfonamides and indoles.
Catalytic Asymmetric Dihydroxylation of Enamides and Application to the Total Synthesis of (+)-Tanikolide
作者:Benoit Gourdet、Hon Wai Lam
DOI:10.1002/anie.201004328
日期:2010.11.8
Asymmetricdihydroxylation of β,β′‐ disubstituted enamides afforded chiral tertiary‐alcohol‐containing α‐hydroxyaldehydes and 1,2‐diols with high enantioselectivity (see scheme). This method was applied to the total synthesis of the antifungal natural product (+)‐tanikolide, as well as the synthesis of an intermediate en route to (S)‐oxybutynin.
Fishing with copper acetylides: Selective alkynylation of heteronucleophiles
作者:Céline Guissart、Michel Luhmer、Gwilherm Evano
DOI:10.1016/j.tet.2018.09.053
日期:2018.11
Copper acetylides are readily available and especially convenient reagents for the alkynylation of a broad range of heteronucleophiles. Upon simple activation with molecular oxygen in the presence of suitable ligands and solvents, they readily transfer their alkyne moiety at room temperature, notably yielding a variety of nitrogen- and phosphorus-substituted alkynes. We report in this manuscript an
乙炔铜很容易获得,尤其是方便的试剂,用于广泛范围的异亲核试剂的炔基化。在合适的配体和溶剂存在下用分子氧简单活化后,它们很容易在室温下转移其炔烃部分,特别是产生各种氮和磷取代的炔烃。我们在这份手稿中报告了基于定量13对该炔基化的化学选择性的广泛研究1 H NMR分析。通过合适的配体/溶剂组合,即使存在大量过量的氮亲核试剂,各种磷基亲核试剂也可以被烷基化,并具有出色的选择性。这种化学选择性的炔基化反应可以进一步扩展到更具挑战性的氮-亲核试剂的选择性炔基化反应,进一步突出了乙炔铜作为炔化剂的合成潜力,可以选择性地“诱捕”亲核试剂而不影响其他亲核试剂。