Chemo-, regio-, and stereoselective hydroboration of conjugated enyne alcohol/amine: facile synthesis of Z , Z -/ Z , E -1,3-dien-1/2-ylboronic ester bearing hydroxyl/amino group
Hydroboration of conjugated enyne alcohol/amine is studied by using copper salts and bis(pinacolato)diboron as pre-catalysts and boron source respectively. It is suggested that the chemo-selectivity is derived from a combined electronic influence of the heteroatoms on the substrate and the ligand on the transition metal. The regioselectivity is probably dominated mainly by electronic effect of the
Rhodium(I)-Catalyzed Intramolecular Hydroacylation of 4,6-Dienals: Novel Synthesis of Cycloheptenones
作者:Yoshihiro Sato、Yoshihiro Oonishi、Miwako Mori
DOI:10.1055/s-2007-983774
日期:2007.7
Rhodium(I)-catalyzedhydroacylation of 4,6-dienals was investigated. Hydroacylation of 4,6-dienals with a substituent at the C7 position produced cycloheptenone derivatives as the major products, while the cyclization of 4,6-dienals with no substituent at the terminus of the diene moiety preferentially gave cyclopentanone derivatives. The olefinic geometry of the diene moiety in 4,6-di-enals also affected
Synthesis of most polyene natural product motifs using just 12 building blocks and one coupling reaction
作者:Eric M. Woerly、Jahnabi Roy、Martin D. Burke
DOI:10.1038/nchem.1947
日期:2014.6
targets, most small-molecule naturalproducts are biosynthesized via iterative coupling of bifunctional building blocks. This suggests that many small molecules also possess inherent modularity commensurate with systematic building block-based construction. Supporting this hypothesis, here we report that the polyene motifs found in >75% of all known polyenenaturalproducts can be synthesized using just
多肽、寡核苷酸和寡糖的固有模块性已被用来实现通用合成平台。重要的是,与这些其他目标一样,大多数小分子天然产物是通过双功能构件的迭代耦合来生物合成的。这表明许多小分子也具有与系统的基于构建块的结构相称的固有模块化性。为了支持这一假设,我们在此报告称,>75% 的已知多烯天然产物中发现的多烯基序只需 12 个结构单元和一个偶联反应即可合成。使用相同的通用逆合成算法和反应条件,该平台能够合成覆盖所有天然产物化学空间的多种多烯框架,并首次全合成多烯天然产物阿尼吡酮 B、毒藻素 A 和神经孢黄素β- D-吡喃葡萄糖苷。总的来说,这些结果表明有可能采用更通用的方法在实验室中制造小分子。
Palladium-Catalyzed Catellani Aminocyclopropanation Reactions with Vinyl Halides
作者:Avinash Khanna、Ilandari Dewage Udara Anulal Premachandra、Paul D. Sung、David L. Van Vranken
DOI:10.1021/ol401383m
日期:2013.6.21
intramolecular aminocyclopropanation of norbornenes with aliphatic vinylhalides in good yields. The reaction tolerates a variety of amine substituents and gives good results with a variety of carbocyclic and oxabicyclic [2.2.1] alkene acceptors. Notably, stabilized enolate nucleophiles were also employed in cyclopropanation reactions.
[structure:see text] The marinenaturalproduct hennoxazole A was synthesized by a convergent approach. The diastereoselective Mukaiyama aldol reaction with beta-alkoxy aldehyde was used to construct the tetrahydropyran segment, and the preparation of the nonconjugated triene moiety was accomplished via S(N)2 displacement of allylic bromide with vinyllithium and Takai's iodoolefination followed by