Cyclization reactions of 2-alkynylbenzyl alcohol and 2-alkynylbenzylamine derivatives promoted by tetrabutylammonium fluoride
摘要:
The regioselectivity of the cyclization reaction of 2-ethynylbenzyl alcohol and 2-ethynylbenzylamine derivatives promoted by TBAF was investigated. Six-membered ring derivatives were obtained from the compounds, which have a butyl group on the triple bond. Whereas five-membered ring products were afforded from the substrates having hydrogen or aromatic substituents. on the acetylene moiety. It was also concluded that both the tetrabutylammonium cation and fluoride anion were essential for the cyclization. Thus, the actual mechanism and catalytic cycle were also suggested. (C) 2001 Elsevier Science Ltd. All rights reserved.
with two N heteroatoms (in ( 1 )) or with N and O heteroatoms (in ( 2 ) and ( 3 )) in axial positions have been prepared and their molecular structures determined by X-ray diffraction. The molecular structures of compounds ( 1–3 ) show trigonal bipyramidal geometry about the central sulfur atom. The rather long axial S–N bonds (1.93 A) in the symmetric spiro- λ 4 -sulfane ( 1 ) exhibit the usual hypervalent
摘要 三种新型 N -乙酰化螺 - λ 4 - 硫烷具有五元螺环(与芳香环稠合)和两个 N 杂原子(在 ( 1 ) 中)或具有 N 和 O 杂原子(在 ( 2 ) 和 ( 3 ) 中)已经制备了轴向位置,并通过 X 射线衍射确定了它们的分子结构。化合物(1-3)的分子结构显示出围绕中心硫原子的三角双锥几何结构。对称螺- λ 4 -硫烷 ( 1 ) 中相当长的轴向 S-N 键 (1.93 A) 表现出通常的高价特性,而 S-N (1.73 和 1.80 A) 和 S-O (2.23 和 2.07 A) ) 不对称螺-λ 4 -硫烷 (2) 和 (3) 中的键长分别对应于拉长的共价 S-N 键和高度极化的 S-O 超价键。每个结构都表现出通常的 S-Car 键长 (1.79–1.81 A)。轴向 NSN/O 和赤道 Car-S-Car 角分别位于 173-179° 和 98-103° 的区间内
Concise synthesis of cyclic carbonyl compounds from haloarenes using phenyl formate as the carbonyl source
作者:Hideyuki Konishi、Hiroki Nagase、Kei Manabe
DOI:10.1039/c4cc09413a
日期:——
Carbonylative cyclization of haloarenes bearing nucleophilic moieties under Pd catalysis has been developed as a general, user-friendly method for access to various cyclic carbonyl compounds.