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Like the aldol addition, the Michael reaction may proceed via an enol, silyl enol ether in the Mukaiyama–Michael addition, or more usually, enolate nucleophile. In the latter case, the stabilized carbonyl compound is deprotonated with a strong base (hard enolization) or with a Lewis acid and a weak base (soft enolization).
It thus serves as a catalyst for Mukaiyama aldol reactions [2] and group-transfer chain-growth polymerization reactions. [3] As a Brønsted base, TTMPP can deprotonate various alcohols, giving nucleophilic alkoxides that can undergo Michael addition reactions. [4] TTMPP can act as a Michael nucleophile itself to catalyze Baylis–Hillman ...
The Mukaiyama aldol addition is a Lewis acid-mediated addition of enol silanes to carbonyl (C=O) compounds. In this reaction, compounds with various organic groups can be used (see educts). [3] A basic version (R 2 = H) without the presence of chiral catalysts is shown below. Simplified overview with a stereocenter
The first two reactions shown below are from the syntheses of (+)-lycoflexine [32] and zaragozic acid C, [33] respectively, which are direct applications of Sakurai and Mukaiyama reactions. The third reaction, en route to (+)-fawcettimine, is a Lewis-acid catalyzed cyclopropane opening that is analogous to a Mukaiyama-Michael reaction. [34]
A Mukaiyama aldol addition (magnesium bromide / toluene) took place between aldehyde 7 and ketene silyl acetal 8 with 71% stereoselectivity to alcohol 9 which was protected as the TBS ether 10 (TBSOTf, 2,6-lutidine). The ester group was reduced with DIBAL to an alcohol and then back oxidized to aldehyde 11 by Swern oxidation.
Michael addition; Michael addition, Michael system; Michael condensation; Michaelis–Arbuzov reaction; Midland Alpine borane reduction; Mignonac reaction; Milas hydroxylation of olefins; Minisci reaction; Mislow–Evans rearrangement; Mitsunobu reaction; Miyaura borylation; Modified Wittig-Claisen tandem reaction; Molisch's test; Mozingo reduction
Lisa Marie Presley was molested by mom Priscilla Presley’s boyfriend, actor and model Michael Edwards, when she was just 10 years old, the late star claims in her new posthumous memoir.. Lisa ...
The mechanism of a Nenitzescu reaction consists of a Michael addition, followed by a nucleophilic attack by the enamine pi bond, and then an elimination. [5]Mechanism for the Nenitzescu indole synthesis