The Cleavage of Three‐Membered Ring Compounds by Transition Metal Organometallic Complexes

Abstract

Transition metal organometallic complexes effect a wide range of useful and interesting cleavage reactions of three‐membered ring compounds. This review examines some recent developments in the organometallic chemistry of cyclopropanes, epoxides, episulfides and azirines. Novel synthetic approaches to heterocyclic [e.g., β γ and δ‐lactones, β‐lactams, isoxazoles, pyrazoles, indoles] and acyclic compounds [β‐diketones, vinyl isocyanates] have been achieved by means of these cleavage reactions.

Transition-Metal-Catalyzed Cleavage of C–N Single Bonds

“…As reported by Alper et al, bicyclic β-lactams 383 could be generated from 2H-azirines and CO in the presence of a catalytic amount of Pd(PPh 3 ) 4 (Scheme 112). 304,305 In the catalytic cycle, the reactive Pd species 384 is generated from Pd(PPh 3 ) 4 Park et al developed a rhodium carbenoid-mediated ringopening of 2H-azirines to construct substituted pyridines 396 (Scheme 114). 308 A variety of 2H-azirines with both electronrich and electron-deficient substituents could react smoothly with a series of diazo compounds to give the corresponding pyridines 396.…”

“…As reported by Alper et al, bicyclic β-lactams 383 could be generated from 2 H -azirines and CO in the presence of a catalytic amount of Pd­(PPh 3 ) 4 (Scheme ). , In the catalytic cycle, the reactive Pd species 384 is generated from Pd­(PPh 3 ) 4 in the presence of CO. 384 then promotes a C–N bond cleavage of the 2 H -azirine via oxidative addition to yield π-allyl intermediate 385 , which reacts with another molecule of the 2 H -azirine to give intermediate 386 . An intramolecular cyclization gives the bicyclic complex 387 , followed by an insertion of Pd into C–N bond to generate intermediate 388 .…”

“…As reported by Alper et al, bicyclic β-lactams 383 could be generated from 2Hazirines and CO in the presence of a catalytic amount of Pd(PPh 3 ) 4 (Scheme 112). 304,305 In the catalytic cycle, the reactive Pd species 384 is generated from Pd(PPh Generally, one molecule of a N-containing compound acts as either a carbon source or a nitrogen source in one reaction via C−N bond cleavage. The whole atom economy is low.…”