Studies on Reactivity ofin situGenerated Allylic Phosphorus Ylides with Aldehydes
نویسندگان
چکیده
منابع مشابه
Double γ-alkylation of allylic phosphorus ylides: a unique access to oxa-bicyclic[3.3.0] diene skeletons.
A new ylide-initiated tandem cyclization reaction based on γ-dialkylation of allylic ylides has been realized, delivering a series of [3.3.0] oxa-bicyclic dienes in high yields with perfect diastereoselectivity.
متن کاملDelineation of the factors governing reactivity and selectivity in epoxide formation from ammonium ylides and aldehydes.
Diastereoselectivity in reactions of aryl-stabilised ammonium ylides are highly sensitive to the nature of the amine and the ylide substituent. DFT calculations are consistent with a mechanism in which reversibility in betaine formation [despite the high energy (and therefore instability) of ammonium ylides] is finely balanced due to the high barrier to ring closure.
متن کاملEffect of Allylic Groups on SN2 Reactivity
The activating effects of the benzyl and allyl groups on S(N)2 reactivity are well-known. 6-Chloromethyl-6-methylfulvene, also a primary, allylic halide, reacts 30 times faster with KI/acetone than does benzyl chloride at room temperature. The latter result, as well as new experimental observations, suggests that the fulvenyl group is a particularly activating allylic group in S(N)2 reactions. ...
متن کاملNi-catalyzed asymmetric reductive allylation of aldehydes with allylic carbonates.
This work features first asymmetric Ni-catalyzed reductive coupling of allylic carbonates with aldehydes, which may proceed via allyl-Ni intermediates although Zn was used as the terminal reductant. Moderate to excellent enantiomeric excess was obtained with excellent functional group tolerance.
متن کاملAn isothiourea-catalyzed asymmetric [2,3]-rearrangement of allylic ammonium ylides.
Benzotetramisole promotes the catalytic asymmetric [2,3]-rearrangement of allylic quaternary ammonium salts (either isolated or prepared in situ from p-nitrophenyl bromoacetate and the corresponding allylic amine), generating syn-α-amino acid derivatives with excellent diastereo- and enantioselectivity (up to >95:5 dr; up to >99% ee).
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ژورنال
عنوان ژورنال: Chinese Journal of Organic Chemistry
سال: 2012
ISSN: 0253-2786
DOI: 10.6023/cjoc201205003