Ruthenium-Catalyzed (2 + 2) Intramolecular Cycloaddition of Allenenes
作者:Moisés Gulías、Alba Collado、Beatriz Trillo、Fernando López、Enrique Oñate、Miguel A. Esteruelas、José L. Mascareñas
DOI:10.1021/ja200784n
日期:2011.5.25
We report a ruthenium-catalyzed (2 + 2) intramolecularcycloaddition of allenes and alkenes. We have found that the use of the ruthenium complex RuH(2)Cl(2)(P(i)Pr(3))(2), which has previously gone unnoticed in catalytic applications, is crucial for the observed reactivity. The reaction proceeds under mild conditions and is fully diastereoselective, providing a practical entry to a variety of bicyclo[3
A catalyst-free method for the highly regioselective chloroboration of allenylsilanes is described. In the presence of BCl3 and 2,6-lutidine, chloroboration of allenylsilanes proceeds smoothly without any catalyst, and the product could be treated with pinacol to afford the corresponding pinacol borates in one-pot reaction. This reaction provides a direct approach to construct valuable 2-silylallylboronate
Borylative Cyclization of 1,6-Allenynes Driven by BCl<sub>3</sub>
作者:Chun-Hua Yang、Xiangkun Sun、Congcong Niu、Zhiwei Zhang、Mingzhu Liu、Fangjie Zheng、Ling Jiang、Xiangtao Kong、Zhantao Yang
DOI:10.1021/acs.orglett.1c03062
日期:2021.10.15
A metal-free intramolecular borylative cyclization of 1,6-allenynes driven by BCl3 was developed. This method provides a general and practical strategy to construct valuable pyrrolidines containing all-carbon quaternary centers or 3,5-dihydroazepine derivatives depending on the substituents of the allene, with conjugative and sterically hindered phenyl groups favoring the latter.
Cobalt/rhodium heterobimetallic nanoparticle-catalyzed carbonylative [2+2+1] cycloaddition of allenes and bisallenes to Pauson–Khand-type reaction products
作者:Ji Hoon Park、Eunha Kim、Hyeong-Mook Kim、Soo Young Choi、Young Keun Chung
DOI:10.1039/b718107h
日期:——
catalytic intra- and intermolecular [2+2+1] cocyclization reactions of allenes and carbon monoxide have been developed. In the Co(2)Rh(2) heterobimetallicnanoparticle-catalyzed carbonylative [2+2+1] cycloaddition of allenes and carbon monoxide, the allenes formally serve both as an excellent alkene- and alkyne-like moiety within a Pauson-Khand-type process.
Highly Regio- and Stereoselective Synthesis of Alkylidenecyclopropanes via Ru(II)-Pheox Catalyzed Asymmetric Inter- and Intramolecular Cyclopropanation of Allenes
An efficient protocol for the synthesis of optically active alkylidenecyclopropanes (ACPs) via the Ru(II)-Pheox catalyzed asymmetric cyclopropanation of allenes has been established. This catalytic system proceeded with high regioselectivity to give the ACP products in high yield with high diastereoselectivity (up to 99/1) and enantioselectivity (up to 99% ee).