Neighboring group participation in Lewis acid-promoted [3 + 4] and [3 + 5] annulations. The synthesis of oxabicyclo[3.n.1]alkan-3-ones
作者:Gary A. Molander、Kimberly O. Cameron
DOI:10.1021/ja00056a002
日期:1993.2
2-(alkoxycarbon)-m-oxabicyclo[3.n.1]alkan-3-ones can be constructed by this process in which two new carbon-carbon bonds are generated. Unusually high regioncontrol is observed, and good to excellent stereochemicalcontrol can be achieved at virtually every position on the new carbocycles. Intramolecular neighboringgroupparticipation is proposed to explain the unusually high selectivities attained in the annulation
作者:Christopher W. am Ende、Zhou Zhou、Kathlyn A. Parker
DOI:10.1021/ja3108577
日期:2013.1.16
completed in 14 steps (longest linear sequence) from commercially available starting materials. The doubly convergent route employs a tandem 5-exo, 6-exo radical cyclization as the key step. This reaction assembles the fully functionalized tetracyclic core and introduces three stereogenic centers. Other effective transformations are the regioselective deoxygenation of an advanced enone intermediate and
新型角鲨烯合酶抑制剂 bisabosqual A 的合成是通过 14 个步骤(最长的线性序列)从市售起始材料完成的。双收敛路线采用串联5-exo、6-exo自由基环化作为关键步骤。该反应组装了完全功能化的四环核心并引入了三个立体中心。其他有效的转化是高级烯酮中间体的区域选择性脱氧以及在酯存在下将三甲基铝化学和非对映选择性加成到酮上。
Substitution reactions of 2-benzenesulphonyl cyclic ethers with carbon nucleophiles
作者:Dearg S. Brown、Maurizio Bruno、Raymond J. Davenport、Steven V. Ley
DOI:10.1016/s0040-4020(01)81323-5
日期:1989.1
Direct substitution of 2-benzenesulphonyl cyclic ethers was studied using a variety of carbon nucleophiles. These nucleophiles included organozinc reagents (derived from aryl, vinyl and alkynyl Grignard reagents) or silyl enolethers, silyl ketene acetals, allylsilanes and trimethylsilylcyanide in the presence of aluminum chloride. A general selectivity for the formation of the trans-product was observed
作者:Barry M. Trost、Hanbiao Yang、Oliver R. Thiel、Alison J. Frontier、Cheyenne S. Brindle
DOI:10.1021/ja067305j
日期:2007.2.1
A ring-expanded bryostatin analogue was synthesized by utilizing a Ru-catalyzed tandem tetrahydropyran formation, a Pd-catalyzed tandem dihydropyran formation, and a ring-closing metathesis (RCM) as key steps. The analogue possesses potent antitumor activity against the NCI-ADR cancer cell line with an IC50 of 123 nM.
Bistrifluoromethanesulfonimide has been used to catalyze C-C bondforming reactions such as Friedel-Crafts, Mukaiyama, 1,2-addition and 1,4-addition as well as C-glycosidation reactions.
双三氟甲磺酰亚胺已用于催化 CC 键形成反应,例如 Friedel-Crafts、Mukaiyama、1,2-加成和 1,4-加成以及 C-糖苷化反应。