Catalytic Cycloisomerization of 1,5‐Enynes to 1,3‐Cyclohexadienes via Ruthenium Vinylidene Intermediates

Abstract

Another way to dienes: The ruthenium-catalyzed 6-endo-cycloisomerization of 1,5-enynes gives the corresponding 1,3-cyclohexadienes in high to excellent yields. This novel synthetic and catalytic method constitutes another way to selectively prepare 1,3-cyclohexadienes, this cyclic diene skeleton being a core subunit in many natural products and a useful building block for a variety of organic transformations.

Transition Metal Vinylidene- and Allenylidene-Mediated Catalysis in Organic Synthesis

“…The reaction of 1,5-enyne 549 in the presence of a diruthenium catalyst gave rise to cyclohexadiene 550 in excellent yield (Scheme ). Similarly, oxirane-tethered 1,5-enynes gave phenol products under a ruthenium catalysis …”

Divergent reaction pathways in gold-catalyzed cycloisomerization of 1,5-enynes containing a cyclopropane ring: dramatic ortho substituent and temperature effects

“…Transition metal-catalyzed enyne cycloisomerization 1 is one of the most important strategies for the construction of cyclic structures from simple acyclic enyne substrates, of which 1,4-, 2 1,5-, 3 1,6- 4 and 1,7-enynes 4k , 5 have been extensively examined. Among a range of transition metal catalysts for enyne cycloisomerization, gold( i ) complexes are the most active and selective catalysts, probably due to relativistic effects.…”

New thioether–dithiolate complexes of Cp∗Ir and some reactivity features

“…The crystallographic data for the complexes 1e8 are summarized in Table 1. (9) 14.9777 (4) 8.5045 (2) 16.6681 (4) 12.0393 (3) 8.0250 (3) 12.0115 (7) 17.7762 (4) b (Å) 9.3981(10) 16.1975 (4) 24.4829 (6) 15.0354 (4) 12.3730 (3) 9.3138 (3) 12.3442 (7) 11.8918 (3) c (Å) 12.2601 (14) 24.7586 (5) 9.1949 (2) 20.4483 (5) 21.5371 (6) 17.0470 (7) 21.5711 (12) 31.1793 (7) a (deg) 109.7210 (10) 95.090 (2) 97.249 (3) 95.006 (3) 104.0970 (10) g …”