Tetrahydroquinoline synthesis

Taclamine, 224 Talampicillin, 438 Talopram, 357 Tamoxifen, 127 Tandamine, 347, 460 Tazolol, 110, 268 Teclozan, 28 Temazepam, 402 Terodiline, 56 Tesicam, 379 Tesimide, 296 Testolactone, 160 Tetrahydropyrimidine synthesis, 303 Tetrahydroquinoline synthesis, 371 Tetrazole synthesis, 301,... 

Table 3 Tetrahydroquinoline synthesis using an aza-Diels-Alder approach (Equation 133)...

Styryl derivatives of 2-aminofurans, as well as alkenyl compounds, also undergo intramolecular cycloaddition and the alkene function can be introduced by Stille coupling of a suitably functionalised aryl iodide. This approach is illustrated by the tetrahydroquinoline synthesis summarised in Scheme 26 (99JOC3595). The iodo derivative 143 is readily prepared from the carbamate ester 142 (67% yield) and Stille coupling with vinyltributyltin gives the styrene 144 (72% yield). Intramolecular cycloaddition and dehydration is then achieved simply by heating compound 144 in toluene under reflux (24 h) to give the tetrahydroquinoline 145 in 79% yield. 

Multicomponent reactions are an increasingly important class of reactions because they combine simplicity, atom economy and efficiency in terms of both yields and the introduction of molecular diversity [52]. These reactions have been described on both solid and soluble supports, as well as giving an easy entry into libraries of compounds. BTSILs are appropriate soluble supports for such reactions. This is illustrated by the tetrahydroquinoline synthesis developed in solution and on solid supports [52]. The reaction of an aniline supported on an ammonium salt in solution of [BuMe3N][NTf2] with benzaldehydes and electron-rich olefins such as styrene, cyclopentadiene and indene in the presence of a trace of TEA, led quantitatively and rapidly (20 to 60 min) to the corresponding tetrahydroquinolines at room temperature according to (Scheme 5.5-36) [21,51]. 

Scheme 15.119 Indoline and tetrahydroquinoline synthesis via a tandem hydroamina-tion/q clization with 1,3-diketone/dehydration.

Scheme 11 Tetrahydroquinoline synthesis employing ring-closing metathesis...

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