Titanocene-Catalyzed Conjugate Reduction of α,β-Unsaturated Carbonyl Derivatives

Abstract

A titanocene-catalyzed conjugate reduction of alpha,beta-unsaturated carbonyl derivatives has been developed. A series of carbonyl compounds including aldehydes, ketones, esters, and amides proved viable in the reduction process providing an efficient, chemoselective method for the catalytic reduction of unsaturated carbonyl derivatives.

Reductive Umpolung Reactions with Low-Valent Titanium Catalysts

“…Furthermore, a titanium(III)‐catalyzed conjugate reduction of α,β‐unsaturated carbonyl derivatives had been reported by Ashfeld et al. in 2010 …”

A Flexible Approach to 6,5‐Benzannulated Spiroketals

“…The resultant enones 7, 18 and 19 were then subjected to chemoselective reduction [8] by employing Cp 2 TiCl 2 , zinc powder and triethylamine hydrochloride to yield protected dihydroxy ketones 20-22 in respectable yields (Table 1). Finally, attention turned to the simultaneous deprotection/cyclisation step.…”

Transition Metal Free Chemoselective Reduction of α,β‐Unsaturated Ketones to Saturated Ketones Using Tosyl Hydrazide as a Hydrogen Donor

“…In addition, Pincer-Pd [3] (Scheme 1, reaction 1) complex and many other transition metals like rhodium, [4] ruthenium, [5] cobalt, [6] indium, [7] titanium [8] and few other catalysts [9] have been used for the reduction of isolated double bonds. In 2002, Kosal and his co-workers [12] have reported chemoselective reduction of α,β-unsaturated carbonyl compounds using Cp 2 TiCl 2 derivative in the presence of Zn dust as a catalyst. [10] In further, Nandy and his group [11] reported reduction of isolated double bond by using ammonium formate as the hydrogen donor with catalytic amount of 10% Pd/C in methanol/THF at reflux temperature.…”