Preparation and reactions of polyfunctional organozinc reagents in organic synthesis

Regioselective preparation of tetrasubstituted alkenes from ketones using Krief`methodology as a key step for a straightforward synthesis of dienynes

“…In a first set of experiments carried out with aldehyde 7a, we envisioned to introduce in a straightforward manner the triple bond and the double bond according to Scheme 3. Indeed, the alkylation of 7a with copper(I) reagent 9 derived from (4-chlorobut-1-ynyl)trimethylsilane prepared from the corresponding zinc derivative 10 furnished in presence of Et 2 O•BF 3 , alcohol 8a in 54% yield; it is worthy of note that this reaction is not reproducible. Subsequent oxidation led to enone 9a in 90% yield which was alkylated with isopropylmagnesium chloride in presence of 2 equivalents of HMPA to give tertiary alcohol 10a in 50% yield beside starting material.…”

Synthesis of amines by the electrophilic amination of organomagnesium, -zinc, -copper, and -lithium reagents

“…This characteristic allows them to tolerate numerous functional groups. 89 To date, only a few electrophilic amination procedures have been reported in the literature employing organozinc reagents. Coleman and coworkers reacted dialkylzinc reagents with chloroamines and obtained the desired amine as a mixture with other amines and ammonia 21,90 Recently, a successful study related to the preparation of tertiary amines by the electrophilic amination of diorganozinc reagents with various N,N-dialkyl-N-chloroamines has been published by Barker and Jarvo.…”

The Conjugate Addition Reaction

“…Me 3 SiCl is also needed for the conjugate addition of organozinc-copper reagents, which may bear additional functionalities [16].…”