Generation of allyl Grignard reagents via titanocene-catalyzed activation of allyl halides
作者:Lauren M. Fleury、Brandon L. Ashfeld
DOI:10.1016/j.tetlet.2010.02.144
日期:2010.5
A protocol for the generation of allylGrignardreagents via the catalytic activation of allyl halides is described herein. Subsequent nucleophilic addition to carbonyl derivatives provided the desired homo allylic alcohols in excellent yields (84–99%). Evidence suggests that titanocene dichloride catalyzes the formation of an allylGrignard species which reacts solely with the carbonyl electrophile
Cooperative Titanocene and Phosphine Catalysis: Accelerated C–X Activation for the Generation of Reactive Organometallics
作者:Lauren M. Fleury、Andrew D. Kosal、James T. Masters、Brandon L. Ashfeld
DOI:10.1021/jo301726v
日期:2013.1.18
transmetalation approach toward the generation of Grignard and organozinc reagents mediated by a titanocene catalyst. This method enables the metalation of functionalized substrates without loss of functional group compatibility. Allyl zinc reagents and allyl, vinyl, and alkyl Grignard reagents were generated in situ and used in the addition to carbonyl substrates to provide the corresponding carbinols in yields
An Organotrifluoroborate-Based Convergent Total Synthesis of the Potent Cancer Cell Growth Inhibitory Depsipeptides Kitastatin and Respirantin
作者:Ramsay E. Beveridge、Robert A. Batey
DOI:10.1021/ol500484f
日期:2014.5.2
The total syntheses of the highly cytotoxic neo-antimycin macrocyclic depsipeptide natural products kitastatin and respirantin have been accomplished in a convergent manner using MNBA promoted esterifications and an efficient C- and N-terminus bis-deprotection/HATU promoted macrolactamization. The first examples of using a prenyltrifluoroborate reagent in additions to carbonyl groups are disclosed