Acid-promoted reaction of trimethylsilylketene bis(ethylthio)acetal with imines. Synthesis of gamma,gamma-bis(ethylthio)allylamines

Acid-catalyzed reaction of silylketene dithioacetal 1 with iminium salts or imines 3b,d-h gave the corresponding gamma,gamma-bis(ethylthio)allylamines 2a-h or 5b,d-h in generally high yields. Similar reactions of 1 with (salicylidene)amines 6a-e afforded 4-amino-2,2-bis(ethylthio)chromans 8a-e in good to moderate yields.     

Lewis acid-promoted Baylis-Hillman-type reaction of alpha,beta-unsaturated ethyl thioester with aldehydes without the use of a Lewis base

The Baylis-Hillman-type reaction of alpha,Beta-ethyl thioacrylate with aldehydes has been achieved using diethylaluminium iodide as the promoter without the direct use of any Lewis bases. The reaction provides an effective access to various alpha-methylene-Beta-hydroxy thioesters.     

A novel approach to Morita-Baylis-Hillman (MBH) lactones via the Lewis acid-promoted couplings of α,β-unsaturated lactone with aldehydes

The Morita-Baylis-Hillman (MBH)-type reaction of α,β unsaturated δ-lactone with various aldehydes has been achieved without the direct use of a Lewis base. The new MBH process can be conveniently carried out by the slow addition of the diethylaluminum iodide into the solution of lactone and aldehyde in dichloromethane at 0°C. Modest to good yields were obtained (50-65%) for eight examples.     

Lewis acid-promoted addition of 1,3-bis(silyl)propenes to aldehydes: a route to 1,3-dienes

The Lewis acid-promoted addition of 1,3-bis(silyl)propenes to aldehydes to provide the corresponding (E)-1,3-dienes in excellent stereoselectivity and good to excellent yields is reported. The procedure is mild, base-free, and operationally straightforward.     

Lewis acid-promoted carbonyl addition of 1,3-bis(silyl)propenes

A novel synthetic protocol for Lewis acid-promoted addition of 1,3-bis(silyl)propenes to N-phenyl glyoxylamide and ethyl glyoxylate is developed. The reaction does not appear to be influenced by the steric bulk of the 1,3-bis(silyl)propenes, and represents a new approach to vinylation of glyoxylates; the products are obtained in good yields.     

Bis(ferrocenium) bis[tetrachloroantimonate(III)] trichloroantimony(III)

In the title compound, [Fe(C₅H₅)₂]₂[SbCl₄]₂[SbCl₃], the cyclo­penta­dienyl rings in both cations are parallel, with a nearly eclipsed conformation. The Sb³⁺ ions are coordinated by six Cl^? ions to form octahedral arrangements, of which two are slightly distorted. These octahedra form infinite chains along the c axis through Cl—Sb—Cl bridges.     

Hexaaquacobalt(II) bis[hydrogen bis(4‐carboxyphenylphosphonate)] dihydrate

The Co^II ion in the title complex salt, [Co(H₂O)₆](C₁₄H₁₃O₁₀P₂)₂·2H₂O or [Co(H₂O)₆][H(C₇H₆O₅P)₂]·2H₂O, resides on an inversion centre and exhibits an octahedral environment formed by six aqua ligands. Two unique acid residues share an H atom between their phosphonate groups, forming a complex monoanion with a very short (P)O...H...O(P) hydrogen bond of 2.435 (2) Å. The crystal structure is layered and consists of thick organic bilayers with hydrated metal [Co(H₂O)₆]²⁺ ions arranged between them. The interior of the bilayer is occupied by the aromatic portions of the complex monoanions and the carboxyl groups, which form hydrogen‐bonded R₂²(8) ring motifs. The phosphonate groups are arranged outwards in order to form the hydrogen‐bonded surfaces of the bilayer. Electrostatic and multiple hydrogen‐bond interactions, established between the coordination and solvent water molecules and the phosphonate O atoms, hold neighbouring bilayers together.     

Polymeric bis[bis(2,2′-bipyridine)­nickel(II)] hexavanadate(V)

The structure of the title compound, μ-hexavanadato(V)-bis­[bis(2,2′-bi­pyridine)­nickel(II)], [{Ni(C₁₀H₈N₂)₂}₂{V₆O₁₇}], is composed of vanadium oxide layers intercalated by complex [Ni(bipy)₂]²⁺ cations (bipy is 2,2′-bi­pyridine). The structure is isomorphous with that reported recently for [Zn(bipy)₂]₂[V₆O₁₇] [Zhang, DeBord, O'Connor, Haushalter, Clearfield & Zubieta (1996). Angew. Chem. Int. Ed. Engl. 35 , 989–991]. The vanadium oxide layers are built up solely from VO₄ tetrahedra by corner sharing and clearly exhibit a sinusoidal ruffling. Two O atoms from a single vanadium oxide layer are coordinated to each Ni atom of the complex cations in a cis fashion, with Ni—O distances of 2.027 (3) and 2.087 (3) Å, thus maintaining the two-dimensional structure.