Catalytic Enantioselective Synthesis of 1,4‐Keto‐Alkenylboronate Esters and 1,4‐Dicarbonyls
作者:Michael Z. Liang、Simon J. Meek
DOI:10.1002/anie.201907757
日期:2019.10
catalytic enantioselective method for the synthesis of 1,4-keto-alkenylboronate esters by a rhodium-catalyzed conjugate addition pathway is disclosed. A variety of novel, bench-stable alkenyl gem-diboronate esters are synthesized. These easily accessible reagents react smoothly with a collection of cyclic α,β-unsaturatedketones, generating a new C-C bond and stereocenter. Products are isolated in up to
Phosphine-Catalyzed Intermolecular Dienylation of Alkynoate with <i>para</i>-Quinone Methides
作者:Zefeng Song、Weijia Wang、Zhixin Liu、Yue Lu、De Wang
DOI:10.1021/acs.joc.1c00226
日期:2021.7.2
An interesting remote δ-C 1,6-addition and an isomerization cascade reaction for phosphine-catalyzed activated alkynes have been disclosed. The products featuring a functional diene and a 1,1-diaryl methyl motif have been obtained in moderate to good yields (30–86%) by applying para-quinone methides (p-QMs) and δ-substituted alkynoate with tributylphosphine (PnBu3) catalysis, along with high regioselectivity
已经公开了一种有趣的远程 δ-C 1,6-加成和膦催化的活化炔烃的异构化级联反应。通过应用对醌甲基化物 ( p -QMs) 和 δ-取代的炔酸酯与三丁基膦 (P n Bu 3 ) 催化,以及高区域选择性和立体选择性(dr > 20:1)。广泛的兼容底物(35 个示例),例如吲哚基、羟吲哚基、酯和肉桂基,扩展了该方法的实用性。还介绍了一种合理的机制及其一些应用。
Synthesis of dibromoolefins via a tandem ozonolysis–dibromoolefination reaction
作者:Brenna Arlyce Brown、Jonathan G.C. Veinot
DOI:10.1016/j.tetlet.2012.11.121
日期:2013.2
In this Letter we outline the synthesis of a variety of dibromoolefins (DBOs) from a series of alkenes by coupling an oxidative cleavage and a reaction with a phosphorous ylide. This approach strategically avoids isolation of reactive aldehyde intermediates and presents one of the few examples coupling carbon–carbon bond formation with ozonolysis.
Synthesis of γ,δ-Unsaturated Esters and Amides via Au(I)-Catalyzed Reactions of Aryl Ynol Ethers or Ynamides with Allylic Alcohols
作者:Souta Misawa、Asaki Miyairi、Yoshihiro Oonishi、Yoshihiro Sato、Steven P. Nolan
DOI:10.1055/a-1559-3020
日期:2021.12
to their inherent unique reactivity. Herein, we report Au(I)-catalyzed hydroalkoxylation/Claisen rearrangement cascade reactions of aryl ynol ethers and ynamides with allylic alcohols. At the first stage (hydroalkoxylation) of this cascade reaction, attack of allylic alcohols to aryl ynol ethers or ynamides occurs at the α-position of the polarized alkynes in a completely regioselective manner. Claisen
炔醇醚和炔酰胺等极化炔烃因其固有的独特反应性而备受关注。在此,我们报告了 Au(I) 催化的芳基炔醇醚和炔酰胺与烯丙醇的加氢烷氧基化/克莱森重排级联反应。在该级联反应的第一阶段(加氢烷氧基化),烯丙醇对芳基炔醇醚或炔酰胺的攻击以完全区域选择性的方式发生在极化炔烃的 α 位。随后发生所得加合物的克莱森重排,分别得到 γ,δ-不饱和酯或酰胺。[Au(IPr)NTf2]催化剂对该反应最有效,反应在温和条件下进行(芳基炔醇醚:在THF中,60°C;在炔酰胺的情况下:在甲苯中,80° C) 以原子经济的方式。
Combining silver- and organocatalysis: an enantioselective sequential catalytic approach towards pyrano-annulated pyrazoles
A one-pot sequential bicatalytic asymmetric Michael addition/hydroalkoxylation provides a new series of pyrano-annulated enantioenriched pyrazole derivatives.