Coordinatively unsaturated ruthenium allenylidene complexes: highly effective, well defined catalysts for the ring-closure metathesis of α,ω-dienes and dienynes
Phosphinite Ligand Effects in Palladium(II)-Catalysed Cycloisomerisation of 1,6-Dienes: Bicyclo[3.2.0]heptanyl Diphosphinite (B[3.2.0]DPO) Ligands Exhibit Flexible Bite Angles, an Effect Derived from Conformational Changes (exo- orendo-Envelope) in the Bicyclic Ligand Scaffold
作者:Ian J. S. Fairlamb、Stephanie Grant、Simona Tommasi、Jason M. Lynam、Marco Bandini、Hao Dong、Zhenyang Lin、Adrian C. Whitwood
DOI:10.1002/adsc.200600346
日期:2006.11
Changes in bidentate ligand structure significantly affect catalytic activity in mono-cationic Pd(II)-catalysed 1,6-diene cycloisomerisation processes to give cyclopentene products. A bicyclo[3.2.0]heptanyl diphosphiniteligand (B[3.2.0]DPO, 3) is the first phosphorus-based bidentate ligand capable of promoting regioselective 1,6-diene cycloisomerisation. Trace quantities of water are essential for
Palladium-Catalyzed Asymmetric Diene Cyclization/Hydrosilylation Employing Functionalized Silanes and Disiloxanes
作者:Tao Pei、Ross A. Widenhoefer
DOI:10.1021/jo015724n
日期:2001.11.1
diallylmalonate (1) and other functionalized 1,6-dienes in the presence of a catalytic 1:1 mixture of (N-N)Pd(Me)Cl [N-N = (R)-(+)-4-isopropyl-2-(2-pyridinyl)-2-oxazoline] [(R)-2] and NaBAr(4) [Ar = 3,5-C(6)H(3)(CF(3))(2)] to form the corresponding silylated cyclopentanes in good yield with high diastereoselectivity. The enantioselectivity of cyclization/hydrosilylation of 1 with disiloxanes and functionalized
Nickel-catalyzed [2 + 2 + 2] cycloaddition of arynes and an unactivated alkene: synthesis of 9,10-dihydrophenanthrene derivatives
作者:Nozomi Saito、Kengo Shiotani、Atsushi Kinbara、Yoshihiro Sato
DOI:10.1039/b907476g
日期:——
A nickel-catalyzed [2+2+2] cycloaddition of two molecules of aryne and an alkene moiety in a alpha,omega-diene afforded 9,10-dihydrophenanthrene derivatives in good yields.
Use of Pentamethyldisiloxane in the Palladium-Catalyzed Cyclization/Hydrosilylation of Functionalized Dienes
作者:Tao Pei、Ross A. Widenhoefer
DOI:10.1021/ol005810u
日期:2000.5.1
[reaction--see text] Pentamethyldisiloxane reacts with a range of functionalized dienes in the presence of a catalytic 1:1 mixture of (N-N)Pd(Me)Cl [N-N = 1, 10-phenanthroline or (R)-(+)-4-isopropyl-2-(2-pyridinyl)-2-oxazoline] and NaBAr(4) [Ar = 3,5-C(6)H(3)(CF(3))(2)] to form the corresponding silylated carbocycles in good yield and with good stereoselectivity. Treatment of these silylated carbocycles
Palladium-Catalyzed Hydroboration/Cyclization of 1,<i>n</i>-Dienes
作者:Shota Kanno、Fumitoshi Kakiuchi、Takuya Kochi
DOI:10.1021/acs.joc.2c02781
日期:2023.2.17
While the hydroboration of alkenes is well established, the corresponding cyclization reaction of dienes remains challenging. Here, we report a new method for hydroboration/cyclization applicable to various 1,n-dienes and hydroboranes. The method features the direct synthesis of borylalkyl cyclopentanes from common 1,6-dienes, which is highlighted by syntheses of elaborated pyrrolidine cores from easily
虽然烯烃的硼氢化反应已经很成熟,但二烯的相应环化反应仍然具有挑战性。在这里,我们报告了一种适用于各种 1, n -二烯和氢硼烷的硼氢化/环化新方法。该方法的特点是从常见的 1,6-二烯直接合成硼烷基环戊烷,并通过从易于获得的二烯丙基胺合成精细的吡咯烷核来突出这一点。值得注意的是,1, n -二烯 ( n > 6) 也会形成五元环,提供“远程”硼氢化/环化,否则很难实现。