Selective reductive carbonyl couplings with titanium

Recent advances of carbonyl olefination via McMurry coupling reaction

“…The compatibility of ether with the McMurry reaction can be depicted by the coupling products, 47, from diether substrate, 46. 50 Additionally, McMurry coupling of two calixanthone, 48, was successfully performed by Agbaria and Biali to form dixanthylene, 49. 51 The results of both experiments ( Fig.…”

“…One example that demonstrates the compatibility of the tosylate group is the synthesis of the compound, 89, through the intermolecular coupling reaction of difunctional substrates, 88. 50 By using TiCl 3 /Zn–Cu system in THF, the product was successfully synthesized with 64% yield. Neither transformation nor substitution occurs during the McMurry reaction ( Fig.…”

Thermochromic Furofurans. IV. Approach to the synthesis of bridgehead substituted furo[3,2-b]furans and side products of McMurry reactions

“…Repeated column chromatography (petroleum ether) of fraction A yielded a yellow zone (Rf = 0,92, CH2C12) containing 44 mg (1,8%) of 11 and two slower moving colorless fractions containing 95 mg (3,8%) of 9b (Rf = 0,90, CH2C12; 0,40, petroleum ether) and 21 mg (1,0%) of 9c (Rf = 0,90, CH2C12; 0,60, petroleum ether). The zone with Rf = 0,70 (CH2C12) gave 23 mg (1,7%) of 12 [8,9] as a light yellow oil.…”

New total synthesis of phenanthrene alkaloids

“…The first total synthesis of a member of this family of natural compounds involved the photochemical electrocyclization of a stilbene compound (2) prepared by mixed dicarbonyl coupling of aldehydes with low valent titanium (3). We now wish to describe the total synthesis of the phenanthrene alkaloids secoglaucine 9 a , N-methylsecoglaucine 9b, and atherosperminine 9 c using a modified approach that seems to be a suitable alternative to the titanium method when the aldehydes required fr coupling are not easily available.…”