Synthesis of 2-Alkylidenecyclopentanones via Palladium-Catalyzed Cross-Coupling of 1-(1-Alkynyl)cyclobutanols and Aryl or Vinylic Halides
作者:Richard C. Larock、Ch. Kishan Reddy
DOI:10.1021/ol000219i
日期:2000.10.1
The palladium-catalyzed cross-coupling of aryl or vinylichalides and 1-(1-alkynyl)cyclobutanols affords good yields of stereoisomerically pure 2-arylidene- or 2-(2-alkenylidene)cyclopentanones, respectively, by a process involving (1) oxidative addition of the organic iodide to Pd(0), (2) carbopalladation of the triple bond of the 1-(1-alkynyl)cyclobutanol, (3) regio- and stereoselective ring expansion
Synthesis of 2-Alkylidenecyclopentanones via Palladium-Catalyzed Carbopalladation/Ring Expansion of 1-(1-Alkynyl)cyclobutanols
作者:Richard C. Larock、Ch. Kishan Reddy
DOI:10.1021/jo010577e
日期:2002.4.1
The palladium-catalyzed cross-coupling of aryl halides or vinylichalides or triflates and 1-(1-alkynyl)cyclobutanols affords good yields of stereoisomerically pure 2-arylidene- or 2-(2-alkenylidene)cyclopentanones, respectively. The process involves (1) oxidative addition of the organic halide or triflate to Pd(0), (2) regioselective, intermolecular carbopalladation of the carbon-carbon triple bond
Palladium-catalyzed ring expansion reaction of 1-alkynylcyclobutanols with aryl iodides: an efficient route to 2-disubstituted methylenecyclopentanones
作者:Li-Mei Wei、Li-Lan Wei、Wen-Bin Pan、Ming-Jung Wu
DOI:10.1016/s0040-4039(02)02581-9
日期:2003.1
The reaction of 1-alkynylcyclobutanols with aryl iodides in the presence of Pd(OAc)2 and Et3N in acetonitrile at 80°C for 24 h gives 2-disubstituted methylenecyclopentan-1-ones in modest to good yields. The tandem insertion-ring expansion process proceeds via the formation of an alkynyl π-complex, followed by migration of a carbon-carbon bond of the tert-alkanol to form the cyclopentanones stereoselectively
Formation of trisubstituted buta-1,3-dienes and α,β-unsaturated ketones <i>via</i> the reaction of functionalized vinyl phosphates and vinyl phosphordiamidates with organometallic reagents
ester functional group with organometallic reagents. We found that the functionalized vinyl phosphates were smoothly converted into tri- and tetrasubstituted buta-1,3-dienes via the reaction with aryllithium reagents. Moreover, the vinyl phosphordiamidates were converted into α,β-unsaturated ketones using Grignard reagents. Based on the performed experiments, we proposed a reaction mechanism, which was
A RuPHOX-Ru catalyzed selective asymmetrichydrogenation of exocyclic α,β-unsaturated ketones has been developed, furnishing the corresponding chiral exocyclic allylic alcohols in high yields and with up to >99.5% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 10000 S/C) without any loss in reaction activity and enantioselectivity. The resulting hydrogenated
已开发出RuPHOX-Ru催化的环外α,β-不饱和酮的选择性不对称氢化,可提供高收率和最高> 99.5%ee的相应手性环外烯丙基醇。该反应可以以克级进行,具有相对较低的催化剂负载量(最高10000 S / C),而没有任何反应活性和对映选择性的损失。所得的氢化产物可以容易地转化为具有高不对称性能的几种生物活性化合物。不对称方案为合成手性环外烯丙基醇提供了一种有效的方法。