Enantio- and Regioselective Conjugate Addition of Organometallic Reagents to Linear Polyconjugated Nitroolefins
作者:Matthieu Tissot、Alexandre Alexakis
DOI:10.1002/chem.201300538
日期:2013.8.19
The copper‐catalysed conjugate addition of trialkylaluminium and dialkylzinc reagents to polyconjugated nitroolefins (nitrodiene and nitroenyne derivatives) is reported. A reversed Josiphos ligand L7 allows for the selective 1,4‐ or 1,6‐addition with high enantioselectivities.
One-Pot Synthesis of Less Accessible <i>N</i>-Boc-Propargylic Amines through BF<sub>3</sub>-Catalyzed Alkynylation and Allylation Using Boronic Esters
作者:Kento Yasumoto、Taichi Kano、Keiji Maruoka
DOI:10.1021/acs.orglett.9b00931
日期:2019.5.3
amines is described via an alkynylation or allylation of alkynyl-substituted N-Boc-imines. Our strategy relies on the BF3-mediated in situgeneration of alkynyl imines followed by alkynylation or allylation with the corresponding boronic esters. A range of lessaccessible N-Boc-propargylic amines were obtained in moderate to good yields under mild and acidic conditions with higher atom economy compared
N-Arylazetidines are efficiently obtained in a three-step procedure, providing a wide diversity of derivatives on multigram scale with overall yields of 21–55%. Cheap or easily available acetanilides are used in an adapted aldolization with aldehydes, furnishing β-hydroxyamides with an 81% average yield over 21 examples. Special Mitsunobu conditions have been developed to ensure the cyclization of
Enantioselective Synthesis of Allenes by Catalytic Traceless Petasis Reactions
作者:Yao Jiang、Abdallah B. Diagne、Regan J. Thomson、Scott E. Schaus
DOI:10.1021/jacs.6b11937
日期:2017.2.8
Allenes are useful functional groups in synthesis as a result of their inherent chemical properties and established reactivity patterns. One property of chemical bonding renders 1,3-substituted allenes chiral, making them attractive targets for asymmetric synthesis. While there are many enantioselective methods to synthesize chiral allenes from chiral starting materials, fewer methods exist to directly
Stereodivergent Aminocatalytic Synthesis of <i>Z</i>
- and <i>E</i>
-Trisubstituted Double Bonds from Alkynals
作者:Leyre Marzo、Javier Luis-Barrera、Rubén Mas-Ballesté、José Luis García Ruano、José Alemán
DOI:10.1002/chem.201603437
日期:2016.11.7
A highly diastereoselectivesynthesis of trisubstituted Z‐ or E‐enals, which are important intermediates in organic synthesis, as well as being present in natural products, is described using different alkynals and nucleophiles as starting materials. Diastereocontrol is mainly governed by the appropriate catalyst. Therefore, those reactions controlled by steric effects, such as the Jørgensen–Hayashi's