In situ Preparation and Subsequent Use of Isomerically Pure E- and Z-Crotylamines in a 3-Aza-Claisen Rearrangement

Synthesis of Highly Substituted Quinolines via a Tandem Ynamide Benzannulation/Iodocyclization Strategy

“… a Conditions: carbamate (1.0 equiv), alkynyl bromide (1.2 equiv), CuSO 4 ·5H 2 O (0.2 equiv), 1,10-phenanthroline (0.4 equiv), K 3 PO 4 (2.0 equiv), toluene, 80–85 °C, 49–70 h. b Isolated yield of products purified by column chromatography. c For the preparation of 9 see ref . d For the preparation of 10 see ref . e For the preparation of 11 , see the Experimental Section. …”

“…A 25 mL pear-shaped flask equipped with a rubber septum and argon inlet needle was charged with carbamate 10 (0.177 g, 1.0 mmol, 1.0 equiv), K 3 PO 4 (0.444 g, 0.21 mmol, 2.0 equiv), CuSO 4 ·5H 2 O (0.026 g, 0.11 mmol, 0.10 equiv), 1,10-phenanthroline (0.036 g, 0.21 mmol, 0.20 equiv), and 0.5 mL of toluene. A solution of 1-bromooctyne 12 (0.217 g, 1.2 mmol, 1.1 equiv) in 0.5 mL of toluene was added via cannula over 1 min (0.5 mL of toluene rinse).…”

The Aza-[2,3]-Wittig Sigmatropic Rearrangement of Acyclic Amines: Scope and Limitations of Silicon Assistance

“…Alternative anion stabilizing groups 13e − g were synthesized in a manner similar to that for 13a − c . The amido nucleophiles were derived from monodeprotection of the product from alkylation of di -tert -butylimidodicarbonate with suitably activated methylene derivatives 18e − g (Scheme ) . It was not possible to prepare the corresponding ketone/aldehyde derivatives in an analogous fashion, so 13i − k were prepared from the Weinreb amide 13h , itself derived from 13a .…”

“…The amido nucleophiles were derived from monodeprotection of the product from alkylation of di-tertbutylimidodicarbonate 27 with suitably activated methylene derivatives 18e-g (Scheme 3). 28 It was not possible to prepare the corresponding ketone/aldehyde derivatives in an analogous fashion, so 13i-k were prepared from the Weinreb amide 13h, itself derived from 13a. To generate a totally resonance unstabilized anion we required the tri-n-butyltin derivative 13l, which was prepared via the alkylation of 19 11b with tributylstannylmethyl methanesulfonate (eq 7).…”