Preparation and some reactions of allylic indium reagents

Abstract

5) (a) Araki, S.; Katsumura, N.; Ito, H.; Butsugan, Y. Tqtrahedron Lett. 1989,30, 1581. (b) Araki, S.; Butsugan, Y.Reactions of 2a-c with maleic anhydride (MA) and benzoquinone (BQ) show strong preference for addition to the "carbonyl" face of the diene. For dimethyl acetylenedicarboxylate (DMAD), attack from this face decreases with successive methylidene substitution while for N-phenyl-1,2,4-triazolinedione (PTAD) the reverse occurs. The consequence of orbital tilting and transition-state steric and torsional interactions cannot alone account for the facial selectivity for the reactions with DMAD and PTAD. Unfavorable orbital interaction of the closed shells of the carbonyl(s) and methylidene(s) syn to the incoming orthogonal A orbital of DMAD is considered to be important.

Structural effects on sigmatropic shifts in heteroaromatic allyl ethersElectronic supplementary information (ESI) available: selected crystal data for compound 7. See http://www.rsc.org/suppdata/p1/b1/b102674g/

“…Myrtenol falls into this category and has been used as a synthon in organic synthesis. 18 Myrtenol has also been used as a chiral modifier in the enantioselective reduction of ketones. 19 Contrary to results for synthesized ethers 3 (R = H, Me, Ph), during attempted preparation of the pseudosaccharyl ether of myrtenol by its reaction with pseudosaccharyl chloride at 40 ЊC, following a route that had been used many times before with similar compounds, none of the required myrtenyl ether (6, Scheme 3) could be isolated.…”

Homoallyl-Substituted Vinylcyclopropanes fromα,β-Unsaturated Ketones and Allylindium Derivatives

“…[3,4] To our knowledge, there is so far only one exception: A direct 1,4-addition does occur, in competition to 1,2-addition, in the reaction of dihalocarbenes with 1,3-dienes which are frozen in a cisoid conformation. [5] We here report on the 1,4-addition of a phosphinidene complex and highlight three exceptional aspects. 1) It is the first genuine 1,4-addition of a phosphinidene complex, 2) it is the first addition of a phosphinidene complex to a benzene ring, and 3) it is, as far as we know, the first [41] cycloaddition to an aromatic ring.…”

“…However, the rearrangement does appear to be facilitated by allylic placement of the C ± OIn bond, because benzophenone does not lead to a cyclopropane product. In general, carbenes [1] and related electron-deficient species such as the metal complexes of phosphinidenes (phosphanediylenes) [RPW(CO) 5 ] [2] react with 1,3-dienes by [21] cycloaddition (1,2-addition) to furnish only vinylcyclopropanes or vinylphosphiranes, respectively. However, as vinylphosphiranes tend to rearrange to the corresponding phospholenes, products are frequently isolated that seemingly result from a formal [41] cycloaddition (1,4-addition).…”

“…Because of its high strain energy and its bent benzene ring, [5]metacyclophane 1 reacts under unusually mild conditions with dienophiles at C8 und C11 by a [42] cycloaddition (Diels ± Alder reaction).…”

“…2). The phosphorus center is slightly more shielded (d( 31 P) 191.1) than in reference compounds (d( 31 P) 208 ± 240 [7a, 8] ); the two olefinic carbon atoms anti to the W(CO) 5 substituents display a strong coupling to the phosphorus atom ( 2 J(P,C) 21.2 and…”