An Organometallic Analogue of the “Criss‐Cross” Cycloaddition Reaction

Abstract

High reactivity characterizes the rhenium vinylidene complex 1, which can function, for example, as a potent 1,3‐dienophile in the [3 + 2] cycloaddition with azines: its reaction with PhHCNNCHPh yields the complex 2 (M = Re), which has an almost planar bridging ligand composed of two condensed five‐membered rings. [2 + 2] Cycloadditions are also possible as demonstrated by the reaction of 1 with tBuNCNtBu, which provides isocyanide complexes.

Metal-Assisted Cycloaddition Reactions in Organotransition Metal Chemistry

“…eq 67). While the carbonyl group in 55 is not attacked by DPNI, the CdN bond of tropone-imine complexes 241 readily reacts with DPNI to give cycloadducts 242, which after decomplexation undergo sigmatropic rearrangement to give 243 and 244, which latter are also A very interesting "criss-cross" reaction between benzalazine and the CdCH 2 double bond of the in situ formed vinylidene complexes 245a,b has been described by Geoffroy et al, 165,180 cf. eq 68.…”

“…The vinylidenerhenium complex 83, or its manganese analogue, adds its CdCH 2 double bond across the CdN double bond in PhNdCHPh 165,180 (Scheme 12) to give the carbene complex 84. This is analogous to the above mentioned cycloaddition of imines with vinylidene iron complexes.…”

Synthesis and Characterization of [OsCl2(=C=CHR)(PPh3)2] and Related Complexes

“…[8,10,13,15Ϫ19,20a,20c,20d,20e,21Ϫ25,28Ϫ38] Reported compounds closely related to 2Ϫ5 include [OsCl 3 (ϵCPh)-(PPh 3 ) 2 ], [35] [OsCl 2 (SCN)(ϵCC 6 H 4 NMe 2 )(PPh 3 ) 2 ], [35] [OsHCl 2 (ϵCRЈ)(PR 3 ) 2 ] (R ϭ Cy, iPr), [19,24,25,36] [OsHCl(OPh)(ϵCMe)(PiPr 3 ) 2 ], [19] and [OsCl 2 (ϵCϪCHϭ CRPh)[P(iPr) 2 CH 2 CO 2 Me)[P(iPr) 2 CH 2 CO 2 )] (R ϭ Ph, Me). [34] The analogous carbyne complex [17] [OsH(OAc)(ϭCϭCH 2 )(PiPr 3 ) 2 ], [21] [OsHCl(ϭCϭCHPh)-(PiPr 3 ) 2 ] [37] and [CpMn(ϭCϭCH 2 )(CO) 2 ], [39] . However, after workup with a procedure similar to that used for the isolation of 6Ϫ8, the isolated solid showed the 31 P{ 1 H} NMR signal of 5 and several unidentified broad peaks.…”

Rhenium(I)‐Catalyzed Generation of α,β‐Unsaturated Carbene Complex Intermediates from Propargyl Ethers for the Preparation of Cycloheptadiene Derivatives

“…[17] Then 1,5-hydride transfer of the benzylic hydrogen onto the vinylidene carbon followed by elimination of benzaldehyde generates a,b-unsaturated carbene complex intermediate E. [18] This intermediate reacts with siloxydiene to give divinylcyclopropane F,w hich undergoes Cope rearrangement to give the product. Thus,o ne or two of the carbonyl ligands of ReX(CO) 5 are liberated by heating and vinylidene intermediate D is generated by the reaction with propargyl ether.…”

“…Thus,o ne or two of the carbonyl ligands of ReX(CO) 5 are liberated by heating and vinylidene intermediate D is generated by the reaction with propargyl ether. [17] Then 1,5-hydride transfer of the benzylic hydrogen onto the vinylidene carbon followed by elimination of benzaldehyde generates a,b-unsaturated carbene complex intermediate E. [18] This intermediate reacts with siloxydiene to give divinylcyclopropane F,w hich undergoes Cope rearrangement to give the product. [19] In conclusion, av ery concise and practical method for generation of simple a,b-unsaturated carbene complex intermediates is realized by the reaction of easily available propargyl ethers with ac atalytic amount of ReI(CO) 5 .…”