Efficient and Direct Nucleophilic Difluoromethylation of Carbonyl Compounds and Imines with Me<sub>3</sub>SiCF<sub>2</sub>H at Ambient or Low Temperature
作者:Yanchuan Zhao、Weizhou Huang、Ji Zheng、Jinbo Hu
DOI:10.1021/ol202208b
日期:2011.10.7
by using a proper Lewis base activator, Me3SiCF2H can efficiently difluoromethylate various aldehydes, ketones, and imines to give the corresponding products in good to excellent yields at room temperature or even at −78 °C.
Microwave-Assisted Solvent-Free Synthesis of Enantiomerically Pure <i>N</i>-(<i>tert</i>-Butylsulfinyl)imines
作者:Juan F. Collados、Estefanía Toledano、David Guijarro、Miguel Yus
DOI:10.1021/jo300919x
日期:2012.7.6
environmentally friendly, and very efficient procedure for the synthesis of opticallypureN-(tert-butylsulfinyl)imines has been developed with microwave-promoted condensation of aldehydes and ketones using (R)-2-methylpropane-2-sulfinamide in the presence of Ti(OEt)4, under solvent-free conditions. This procedure allows for the preparation of a variety of sulfinyl aldimines with excellent yields and purities
Asymmetric Synthesis of Amines by the Knochel-Type MgCl<sub>2</sub>-Enhanced Addition of Benzyl Zinc Reagents to <i>N</i>-<i>tert</i>-Butanesulfinyl Aldimines
作者:Andrew W. Buesking、Tyler D. Baguley、Jonathan A. Ellman
DOI:10.1021/ol103002t
日期:2011.3.4
The MgCl2-enhanced addition of benzyl zinc reagents to N-tert-butanesulfinyl imines proceeds readily at room temperature to afford the N-tert-butanesulfinyl-protected amine products in good yields and diastereomeric ratios. This method is functional group tolerant in both the imine substrate and benzyl zinc coupling partner. Moreover, benzyl zinc reagentaddition to the N-tert-butanesulfinyl imine
Carbamoyl Anion Addition to <i>N</i>-Sulfinyl Imines: Highly Diastereoselective Synthesis of α-Amino Amides
作者:Jonathan T. Reeves、Zhulin Tan、Melissa A. Herbage、Zhengxu S. Han、Maurice A. Marsini、Zhibin Li、Guisheng Li、Yibo Xu、Keith R. Fandrick、Nina C. Gonnella、Scot Campbell、Shengli Ma、Nelu Grinberg、Heewon Lee、Bruce Z. Lu、Chris H. Senanayake
DOI:10.1021/ja402647m
日期:2013.4.17
Carbamoyl anions, generated from N,N-disubstituted formamides and lithium diisopropylamide, add with high diastereoselectivity to chiral N-sulfinyl aldimines and ketimines to provide α-amino amides. The methodology enables the direct introduction of a carbonylgroup without the requirement of unmasking steps as with other nucleophiles. The products may be converted to α-amino esters or 1,2-diamines
Chiral Bifunctional Phosphine Ligand Enables Gold-Catalyzed Asymmetric Isomerization and Cyclization of Propargyl Sulfonamide into Chiral 3-Pyrroline
作者:Xinpeng Cheng、Liming Zhang
DOI:10.1021/acs.orglett.1c02896
日期:2021.11.5
This work details an asymmetric gold-ligand cooperativecatalysis that transforms readily accessible chiral/achiral propargylic sulfonamides into chiral 3-pyrrolines. A bifunctional biphenyl-2-ylphosphine ligand featuring a chiral tetrahydroisoquinoline fragment is essential for the observed metal–ligand cooperation and the asymmetric induction. 2,5-cis-3-Pyrrolines are formed with excellent diastereoselectivities