Studies Directed toward the Total Synthesis of Azasteroids. I. 3,4-Cyclopenteno-5,6-dihydropyridines and 6,6-Tetramethylene-5,6-dihydro-1,3-oxazines1-3
Pd(0)-Catalyzed Oxy- and Aminoalkynylation of Olefins for the Synthesis of Tetrahydrofurans and Pyrrolidines
摘要:
The first Pd(0)-catalyzed intramolecular oxy- and aminoalkynylation of nonactivated olefins is reported. The reaction gives access to important tetrahydrofuran and pyrrolidine heterocycles with high diastereoselectivity. The unique synthetic potential of acetylenes is further exploited to access key building blocks for the synthesis of bioactive natural products.
Palladium-Catalyzed Synthesis of 2,1‘-Disubstituted Tetrahydrofurans from γ-Hydroxy Internal Alkenes. Evidence for Alkene Insertion into a Pd−O Bond and Stereochemical Scrambling via β-Hydride Elimination
作者:Michael B. Hay、John P. Wolfe
DOI:10.1021/ja054754v
日期:2005.11.30
diastereoselectivity in reactions of acyclic internal alkene substrates likely derives from a series of reversible β-hydride elimination and σ-bond rotation processes that occur following a rare intramolecular alkene syn-insertion into an intermediate Pd(Ar)(OR) complex. In addition, these studies shed light on the chemoselectivity of insertion, suggesting that the alkene inserts into the Pd−O bond in preference
Stereoselective Synthesis of Tetrahydrofurans via the Palladium-Catalyzed Reaction of Aryl Bromides with γ-Hydroxy Alkenes: Evidence for an Unusual Intramolecular Olefin Insertion into a Pd(Ar)(OR) Intermediate
作者:John P. Wolfe、Michael A. Rossi
DOI:10.1021/ja0394838
日期:2004.2.1
A new, stereoselective method for the synthesis of substituted tetrahydrofurans from gamma-hydroxy alkenes that forms both a C-C and a C-O bond with diastereoselectivities of up to >20:1 is described. Initial mechanistic studies that suggest the reactions proceed via the intramolecular insertion of an olefin into a Pd(Ar)(OR) intermediate are discussed.
描述了一种新的立体选择性方法,用于从 γ-羟基烯烃合成取代的四氢呋喃,该方法形成 CC 和 CO 键,非对映选择性高达 > 20:1。初步的机理研究表明反应是通过烯烃分子内插入 Pd(Ar)(OR) 中间体进行的。