(−)-Complanine, an inflammatory substance of marine fireworm: a synthetic study
作者:Kazuhiko Nakamura、Yu Tachikawa、Daisuke Uemura
DOI:10.3762/bjoc.5.12
日期:——
The synthesis of (−)-complanine, an inflammatory substance of Eurythoe complanata, was accomplished by a “chiral synthon” approach. The absolute configuration of this molecule was determined to be R.
Construction of Hexahydrophenanthrenes By Rhodium(I)-Catalyzed Cycloisomerization of Benzylallene-Substituted Internal Alkynes through C−H Activation
作者:Yasuaki Kawaguchi、Shigeo Yasuda、Chisato Mukai
DOI:10.1002/anie.201605640
日期:2016.8.22
The treatment of benzylallene‐substituted internal alkynes with [RhCl(CO)2]2 effects a novel cycloisomerization by C(sp2)−H bond activation to produce hexahydrophenanthrene derivatives. The reaction likely proceeds through consecutive formation of a rhodabicyclo[4.3.0] intermediate, σ‐bond metathesis between the C(sp2)−H bond on the benzene ring and the C(sp2)−RhIII bond, and isomerization between
Scandium‐ or hafnium‐catalyzed [6+1] annulation reactions of 2‐cyano‐1‐propargyl‐ and 2‐alkynyl‐1‐cyanomethyl‐indoles with Reformatsky reagent delivered 8‐ and 9‐substituted‐azepino[1,2‐a]indole amines in good to high yields.
Synthesis of 1,2-bisalkylidenecyclopentanes from 1,6-allenynes via stereoselective addition of nucleophiles to ruthenacyclopentenes
作者:Nozomi Saito、Yuh Kohyama、Yuki Tanaka、Yoshihiro Sato
DOI:10.1039/c2cc30640a
日期:——
Ruthenium-catalyzed cyclization of 1,6-allenynes occurs via the addition of heteroatom nucleophiles to ruthenacyclopentenes, providing functionalized 1,2-bisalkylidenecyclopentanes in a highly regio- and stereoselective manner.
intermediate carrying a carbonyl group at C6. Asymmetric syntheses of the bicyclic C6-C14 ethynyl building blocks were carried out starting fromachiral bicyclic C6-C12 ketones by using the chiral lithium amide method. In the course of these syntheses, a new method for the introduction of an ethynyl group at the alpha-position of the carbonyl group of a ketone with formation of the corresponding homopropargylic