Regioselective Synthesis of Vinyl Halides, Vinyl Sulfones, and Alkynes: A Tandem Intermolecular Nucleophilic and Electrophilic Vinylation of Tosylhydrazones
作者:Devi Prasan Ojha、Kandikere Ramaiah Prabhu
DOI:10.1021/ol503114n
日期:2015.1.2
in tandem at the carbene center to install an electrophile and a nucleophile on the same carbon. This metal-free concept, which is unprecedented, has been illustrated by regioselectivesynthesis of a variety of vinyl halides, vinyl sulfones, and alkyne derivatives.
Cyclopropenylcarbinol Derivatives as New Versatile Intermediates in Organic Synthesis: Application to the Formation of Enantiomerically Pure Alkylidenecyclopropane Derivatives
作者:Samah Simaan、Ahmad Masarwa、Elinor Zohar、Amnon Stanger、Philippe Bertus、Ilan Marek
DOI:10.1002/chem.200901074
日期:2009.8.24
The copper‐catalyzed carbomagnesiation (or hydrometalation) reaction of chiralcyclopropenylcarbinolderivatives, obtained by means of a kinetic resolution of secondary allylic alcohols, leads to an easy and straightforward preparation of enantiomericallypurealkylidenecyclopropanederivatives. The reaction mechanism is composed of a syn‐carbometalation followed by a syn‐elimination reaction. To gain
γ-Selective directed catalytic asymmetric hydroboration of 1,1-disubstituted alkenes
作者:Sean M. Smith、Gia L. Hoang、Rhitankar Pal、Mohammad O. Bani Khaled、Liberty S. W. Pelter、Xiao Cheng Zeng、James M. Takacs
DOI:10.1039/c2cc36199j
日期:——
Directed catalytic asymmetric hydroborations of 1,1-disubstitutedalkenes afford gamma-dioxaborato amides and esters in high enantiomeric purity (90-95% ee).
A catalytic allylic cation-induced intermolecular allylation-semipinacol rearrangement
作者:Ming-Hui Xu、Kun-Long Dai、Yong-Qiang Tu、Xiao-Ming Zhang、Fu-Min Zhang、Shao-Hua Wang
DOI:10.1039/c8cc04285c
日期:——
A catalytic intermolecular semipinacol rearrangement induced by allylic carbocations has been realized. This tandem reaction is highly efficient under the catalysis of ZnBr2, generating a wide range of α-homoallyl substituted ketones which contain all-carbon quaternary centres in good to excellent yields (up to 98%) with moderate to high diastereoselectivities (up to >20 : 1). Synthetic application
Synthesis of 1,1-Disubstituted Ethenes by Means of Sequential Cross-Coupling Reactions
作者:V. Fiandanese、G. Marchese、F. Naso、L. Ronzini
DOI:10.1055/s-1987-28164
日期:——
A variety of 1-alkenes are synthesized in 63-91% yields by means of sequential cross-coupling reactions of Grignard reagents with readily available or commercial starting materials, in the presence of transition-metal catalysts.