The palladium-catalyzed cross-coupling reaction of aryl iodides with 3,3,3-triethoxy-1-propyne gave 1-aryl-3,3,3-triethoxy-1-propynes which were converted to the corresponding ethyl arylpropiolates. The arylpropiolates were also synthesized from the cross-coupling reactions of aryl iodides with 2-ethoxycarbonyl-1-ethynylzinc chloride or ethyl (tributylstannyl)propiolate, but the reactions were not generally applicable.
Straightforward Synthesis of 2‐Aryl‐1‐alkynylphosphonates and Arylpropiolates
作者:Delphine Lecerclé、Céline Mothes、Frédéric Taran
DOI:10.1080/00397910701226830
日期:2007.4.1
Abstract A protocol for the direct cross coupling of trialkylsilyl‐alkynes bearing electron‐withdrawing groups and aryl halides using a Pd/Ag catalytic system is described. The procedure allows the straightforward synthesis of a variety of alkynylphosphonates and aryl propiolates derivatives in good yields.
α,β-Unsaturated amides play a vital role in natural products, pharmaceuticals, organic synthesis, and functional materials. Herein, we disclosed a regio- and stereoselective hydroaminocarbonylation of unsymmetrical internal alkynes via palladium catalysis to synthesize α,β-unsaturated amides. This protocol features excellent regio- and exclusive (E)-stereoselectivity, high atom and step-economy, broad
α,β-不饱和酰胺在天然产物、药物、有机合成和功能材料中发挥着至关重要的作用。在此,我们公开了通过钯催化对不对称内炔烃进行区域选择性和立体选择性氢化氨基羰基化合成 α,β-不饱和酰胺。该协议具有出色的区域和排他 ( E ) 立体选择性、高原子和阶梯经济性、广泛的底物范围和官能团耐受性。
Regioselective synthesis of spirocyclic pyrrolines <i>via</i> a palladium-catalyzed Narasaka–Heck/C–H activation/[4 + 2] annulation cascade reaction
A novel palladium-catalyzed spirocyclization through sequential Narasaka–Heck cyclization, C–Hactivation and [4 + 2] annulation has been developed. In this reaction, cheap and readily available 2-chlorobenzoic acid or ethyl phenylpropiolate was employed as the C2 insertion unit to react with γ,δ-unsaturated oxime ester. The key step in this transformation is the regioselective insertion of the C2
A visible light photocatalytic [3+2] cycloaddition of alkynes with readily accessible organic iodides as the C3 synthon is developed herein. By merging halogen atomtransfer (XAT) and hydrogen atomtransfer (HAT), alkyl/aryl iodides serve as a formal diradical precursor and add across C-C triple bonds to deliver a number of functionalized cyclopentanes in moderate to high yields with exceptional regio-