Shapeshifting Gabriel Amine Synthesis with Iodo-BCPs.

The Gabriel amine synthesis is a textbook method for the preparation of primary amines from alkyl halides. In this work, we demonstrate a Gabriel amine synthesis with iodo-bicyclopentanes to make aminomethyl bicyclobutanes. DFT studies support the concerted rearrangement of a bicyclo[1.

Stereo-, Regio-, and Chemoselective [3 + 2]-Cycloaddition of (2E,4E)-Ethyl 5-(Phenylsulfonyl)penta-2,4-dienoate with Various Azomethine Ylides, Nitrones, and Nitrile Oxides: Synthesis of Pyrrolidine, Isoxazolidine, and Isoxazoline Derivatives and a Computational Study.

One-pot chemo-, regio-, and stereoselective synthesis of series of heterocyclic and spiroheterocyclic compounds was accomplished through mono- and bis[3 + 2]-cycloaddition reactions of (2E,4E)-ethyl 5-(phenylsulfonyl)penta-2,4-dienoate as a dipolarophile with azomethine ylides, nitrones, and nitrile oxides in good yields. The structures of the products were established by spectroscopic techniques as well as by single-crystal XRD study, and DFT calculations were performed to further understand the mechanism of this [3 + 2]-cycloaddition reaction.

Ethyl (2E,4E)-5-(3-bromo-phenyl-sulfon-yl)penta-2,4-dienoate.

In the title compound, C13H13BrO4S, both C=C double bonds adopt an E conformation. The S atom has a distorted tetra-hedral geometry with bond angles ranging from 102.17 (13) to 119.

Ethyl (E)-3-[1'-ethyl-2-oxo-4'-(phenyl-sulfon-yl)-2H-spiro-[acenaphthyl-ene-1,2'-pyrrolidine]-3'-yl]acrylate.

In the title compound, C(28)H(27)NO(5)S, the five-membered pyrrolidine ring, which exhibits an envelope conformation (the C atom at the spiral junction being the flap atom), makes dihedral angles of 57.37 (10) and 86.84 (8)°, respectively, with the phenyl ring and the acenaphthyl-ene ring system.

(2E,4E)-Ethyl 5-(phenyl-sulfon-yl)penta-2,4-dienoate.

In the title compound, C(13)H(14)O(4)S, both C=C double bonds adopt an E conformation. In the crystal, mol-ecules are linked into centrosymmetric R(2) (2)(14) dimers via pairs of C-H⋯O hydrogen bonds.