Enantioselective Addition of Alkynyl Ketones to Nitroolefins Assisted by Brønsted Base/H‐Bonding Catalysis
作者:Teresa E. Campano、Igor Iriarte、Olatz Olaizola、Julen Etxabe、Antonia Mielgo、Iñaki Ganboa、José M. Odriozola、Jesús M. García、Mikel Oiarbide、Claudio Palomo
DOI:10.1002/chem.201805542
日期:2019.3.21
sets of enolizable alkynyl ketones (including methyl ynones with α‐aryl, α‐alkenyl, and α‐alkoxy groups) were able to react smoothly with nitroolefins with the assistance of bifunctional Brønsted base/H‐bond catalysts to provide adducts with two consecutive tertiary stereocenters in a highly diastereo‐ and enantioselective fashion. Further transformation of the obtained adducts into optically active acyclic
A straightforward synthesis of selenylative carbo‐spirocyclisation from homologated‐ynones is presented trough visible light assisted intramolecular dearomatization. In the process, the substituted spiro‐triene‐2,8‐dione was readily transformed into various spiro‐cycles and substituted 2‐naphthols.
A variety of 4,5-dihydrofuro[2,3-b]azocin-6-one derivatives were expediently assembled through Au(I)-catalyzed cyclization and 2-(tert-butyl)-1,1,3,3-tetramethylguanidine (BTMG)-mediated [4+4] annulation reactions of enyne-amides and ynones. The reactions exhibit high efficiency with excellent regio- and diastereoselectivity. A broad spectrum of substrates was utilized. The products with an eight-membered
通过 Au(I) 催化环化和 2-(叔丁基)-1,1,3,3-四甲基胍,方便地组装了多种 4,5-二氢呋喃[2,3- b ]azocin-6-one 衍生物(BTMG)-介导的烯炔酰胺和炔酮的[4+4]环化反应。该反应表现出高效率以及出色的区域和非对映选择性。使用了广泛的底物。具有八元环的产品可能在生物化学和医学科学中有用。此外,产品可以很容易地转化为各种衍生物。
DBU-Promoted Tandem Cyclization of Ynones and Diazo Compounds: Direct Synthesis of Eight-Membered Cyclic Ethers
efficient method for the synthesis of fused eight-membered oxocino[2,3-c] pyrazoles from readily available acyclic starting materials in a single step. This reaction allows the formation of four new bonds and two rings in a highly regio- and diastereoselective manner, where twoadjacentstereocenters are created simultaneously in an atom-economic manner.
开发了一种新型 DBU 促进的炔酮与重氮化合物作为 N 端亲电子试剂的串联环化反应。该反应提供了一种简单有效的方法,用于从容易获得的无环起始材料一步合成稠合八元氧辛基[2,3- c ]吡唑。该反应允许以高度区域和非对映选择性的方式形成四个新键和两个环,其中以原子经济的方式同时创建两个相邻的立体中心。