Revision of the Absolute Configuration of Salicylihalamide A through Asymmetric Total Synthesis

A Highly Enantioselective Catalyst for the Asymmetric Nozaki–Hiyama–Kishi Reaction of Allylic and Vinylic Halides

“…The related bmethylallyl halides (Table 1, entries 4 and 5) reacted just as smoothly as the allyl halides. [12,14,15] Again, after optimizing the reaction temperature, coupling with allyl bromide occurred with high enantioselectivity (92 % ee). As a model for projected applications in polyketide natural-product synthesis, we tested PMBprotected 3-hydroxypropanal (PMB = para-methoxybenzyl), shown in entry 6 of Table 1.…”

Organic Azides: An Exploding Diversity of a Unique Class of Compounds

“…Enamides were prepared by Kitahara and co‐workers by rearrangement of α,β‐unsaturated acyl azides to alkenyl isocyanates 133 and subsequent addition of nucleophiles 174. 175 The reaction sequence was used for the preparation of a series of natural products such as the lansiumamides A–C and lansamide‐I ( 136 ; Scheme ),176 coscinamide, chondriamide, igziamide,174 salicylihalamide,177 apicularen A,178 and others 179…”

Recent Methods for the Synthesis of (E)‐Alkene Units in Macrocyclic Natural Products

“…On the other hand, De Brabander et al obtained a 10:1 ratio of (E)-22 c/(Z)-22 c when they exposed a monosubstituted olefin analogue of 21c to catalyst 7 in dichloromethane, [31] and Labrecque et al…”

“…[32] These results can be explained by the nature of the RCM catalyst, as shown by De Brabander: [31] With the first-generation catalyst 7 kinetic ratios are obtained, while thermodynamic equilibrium is reached with the more active second-generation catalysts, as it is the case for herbarumin I (Scheme 6).…”