Design, synthesis and application of a new type of bifunctional Le-Phos in highly enantioselective γ-addition reactions of N-centered nucleophiles to allenoates
Manganese-Catalyzed C−H Annulation of Ketimines with Allenes: Stereoselective Synthesis of 1-Aminoindanes
作者:Chong Lei、Lijie Peng、Ke Ding
DOI:10.1002/adsc.201800465
日期:2018.8.6
A manganese‐catalyzed C−H annulation of ketimines with poly‐substituted ester‐activated allenes toward the synthesis of 1‐aminoindanes bearing two vicinal all‐substituted carbon stereocenters and an exocyclic double bond was developed. The reaction features high diastereoselectivity, high E/Z selectivity, 100% atom‐economy, broad substrate scope and good functional group tolerance.
Intramolecular Alkynylogous Mukaiyama Aldol Reaction Starting from Bicyclic Alkanones Tethered to Alkynyl Esters: Formal Total Synthesis of (±)-Hamigeran B
esters tethered to bicycloalkanones leads to the formation of tricyclic allenoates with total diasteroselectivity at the ring junction. An intramolecular alkynylogous Mukaiyama aldol reaction promoted by a TBSOTf/NEt3 dual activation is involved. This novel methodology was illustrated by a formaltotalsynthesis of (±)‐hamigeran B.
选择环:叔丁基二甲基甲硅烷基叔丁基硫酸盐(TBSOTf)/ NEt 3处理与双环烷酮相连的炔基酯会形成三环烯酸酯,在环结处具有总的非对映选择性。涉及由TBSOTf / NEt 3双重激活促进的分子内的醇酸Mukaiyama aldol反应。(±)-hamigeran B的正式总合成说明了这种新颖的方法。
Enantioselective total synthesis of (+)-ibophyllidine via an asymmetric phosphine-catalyzed [3 + 2] annulation
作者:Ian P. Andrews、Ohyun Kwon
DOI:10.1039/c2sc20468a
日期:——
In this study we performed the total synthesis of the terpene indole alkaloid (+)-ibophyllidine through a pathway involving asymmetric phosphine catalysis, with our novel l-4-hydroxyproline-derived chiral phosphine mediating the key [3 + 2] annulation. Hydrogenation of the [3 + 2] adduct allowed the rapid formation of the stereochemically dense pyrrolidine ring of (+)-ibophyllidine in excellent yield
Design and Synthesis of Flavonoidal Ethers and Their Anti-Cancer Activity In Vitro
作者:Lu Jin、Meng-Ling Wang、Yao Lv、Xue-Yi Zeng、Chao Chen、Hai Ren、Heng Luo、Wei-Dong Pan
DOI:10.3390/molecules24091749
日期:——
modified flavonoid derivatives were designed, synthesized, and evaluated for their anti-canceractivities. The results showed that compounds 4b, 4c, 4e, 5e, and 6b exhibited better in vitro inhibitory activity against several cancer cell lines than their precursors. Preliminary structure–activity relationship studies indicated that, in most of the cancer cell lines evaluated, the substitution on position
Synthesis of Substituted Coumarins via Brønsted Acid Mediated Condensation of Allenes with Substituted Phenols or Anisoles
作者:Sundae Kim、Dongjin Kang、Chang-Hee Lee、Phil Ho Lee
DOI:10.1021/jo301086k
日期:2012.8.3
Coumarins were obtained from the condensation of electron-rich arenes with allenes in the presence of TfOH in good yield. Depending on the substituent pattern of allenes employed, the general synthetic method of 4-substituted and 3,4-disubstituted 3-arylcoumarins has been developed. Readily available allenes were employed as the three-carbon atom sources constituting the coumarin skeleton.