Dipolar cycloadditions in solid-phase organic synthesis (SPOS)

Abstract

We present a concise review of polymer-supported 1,3-dipolar cycloaddition reactions. Nitrile oxide and azomethine ylides constitute the two types of 1,3-dipoles which have been used in conjunction with solid-phase organic synthesis. These cycloaddition reactions on solid phase are generally of equal or greater efficiency than the analogous solution-phase reactions.

One-Pot Synthesis of Triazolobenzodiazepines Through Decarboxylative [3 + 2] Cycloaddition of Nonstabilized Azomethine Ylides and Cu-Free Click Reactions

“…1,3-Dipolar cycloaddition of primary amino esters, aldehydes, and activated alkenes is a well-established three-component reaction [16,17,18,19,20,21]. The azomethine ylides derived from deprotonation of iminium ions are CO 2 R-stabilized ylides A (Figure 2A) [22,23,24,25,26,27,28,29,30].…”

Advances in Solid-Phase Cycloadditions for Heterocyclic Synthesis

“…Solid-phase 1,3-dipolar cycloadditions have been used to prepare libraries of monocyclic five-membered heterocycles and fused derivatives. Because early work in this area has already been reviewed, 2 70 The 1,3-dipoles were generated from resin-bound R-silylimines 89 by treatment with trifluorophenylsilane in toluene at 40 or 60°C for 48 h. The reaction was performed in the presence of different cyclic and acyclic dipolarophiles to yield diverse cycloadducts, which were cleaved from the resin with TFA.…”

Chemo‐ and Regioselectivity Enhancement in Solid‐Supported Reactions

“…57 Typically, chemoselectivity is high, and the solid support provides only a mechanism for the rapid preparation of pure compounds in a parallel fashion; however, in select cases the solid support has been demonstrated to enhance both the chemo-and the regioselectivity of the reaction. 58 The 1,3-dipolar cycloaddition has been employed in the synthesis of tetrahydrofurans via the reaction of a 1,5-diene 107 with a nitrile oxide to generate an isoxazoline intermediate 108.…”