110 / 2023-10-06 21:49:29

Silver catalyzed selective tandem cyclization of phosphite with 2-alkyne-3-pyridinecaldehyde

Selective synthesis; Tandem cyclization; Pyridine-dihydrofuran

Phosphorus in Synthetic Chemistry > 1) Phosphorus compounds as catalysts

Silver catalyzed selective tandem cyclization of phosphite with 2-alkyne-3-pyridinecaldehyde

Xingyu Tu，Zhiwei Miao <sup>*

1</sup>State Key Laboratory and Institute of Elemento-Organic Chemistry, University of Nankai, Weijin Road 94, Tianjin, 300071

^*E-mail: miaozhiwei@nankai.edu.cn

Abstract: The selective synthesis of phosphorylated pyridine-dihydrofuran and their reaction mechanism have been developed. The reaction of 2-alkyne-3-pyridinealdehyde with phosphite proceeded smoothly to give target products in the presence of a catalytic amount of silver nitrate(Figure 1). The core of this work is the control of two types of selectivity during the reaction process: one is chemical selectivity, where the addition reaction of phosphite with aromatic aldehydes has a strong tendency towards [1,2]-Phospha-Brook rearrangement, which competes with the cyclization reaction; Second, there is a selectivity of regions. During the cyclization process, the attack of oxygen on different carbon atoms in the triple bond will result in five- or six-membered ring products.Only using pyridine aldehyde derivatives as substrates in the silver catalysis system can ultimately lead to the formation of pentacyclic products, which suggests that the silver catalyst and the pyridine ring may be the key to changing the reaction mechanism. We verified this conjecture through computational chemistry methods.



Fig. 1 Reactions of Phosphite with Alkynyl Substituted Aromatic Aldehydes under Different Conditions



Keywords：Selective synthesis; Tandem cyclization; Pyridine-dihydrofuran



Reference

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