Reactions of dichlorocarbene with olefins temperature dependence of relative reactivities

Kinetic Study of Chemically Activated 1,1‐Dichlorocyclopropanes, I

“…the addition is stereospecific. Following the arguments of Skell and Cholod [5] we conclude that singlet CC1, was formed from the silanes. For further verification in some reactions with cis-butene-2 and trans-butene-2 oxygen was added in a 2.5-fold excess in order to quench triplet CC1,.…”

“…In order to obtain more detailed information RRKM-calculations are being undertaken at present for all reactions discussed here. Relative rate constants for the addition of CC1, to olefins in condensed phases .are reported by Skell and Cholod [5]. It is an unsolved question whether the reaction cross sections vary appreciably for the olefins used in our experiments.…”

Advanced Organic Chemistry

“…For this reason, it is ~ R2C=CHCR' + 1,2-reduction 1,4-reduction leading to saturated alcohol fairly common to find both saturated and unsaturated alcohols from NaBlit or LiAllit reduction of conjugated unsaturated ketones. 31 The extent of reduction to the saturated alcohol is usually greater with NaBlit than with LiAllit. Diisobutylaluminum hydride has been recommended for reduction of enones to allylic alcohols, since this reagent has not been observed to cause reduction of the adjacent double bond.32 If it is desired to reduce the double bond without involving 28.…”

“…The elimination might be concerted, or it might take place via a four-membered dihydrooxaphosphetane intermediate. 31 It has also been suggested that the dihydrooxaphosphetane intermediate might be formed directly, without the intermediacy of the betaine, by a cycloaddition process. 32 Alkylphosphonium salts are only weakly acidic.…”

Phasentransfer‐katalysierte Zweiphasenreaktionen in der präparativen organischen Chemie

“…Eine Untersuchung der Wirksamkeit der verwendeten n-Alkyltriathylammoniumsalze in Abhangigkeit von der Kettenlange zeigte ein Maximum bei der n-Hexylverbindung. Zu kiirzeren Resten sank die Katalysatoraktivitat stark, zu hoheren ein wenig ab[1061.Die katalysierte Addition von Phenylacetonitrilen an Acetylene ergibt(27) (R = H, Ph, SR) oder im Falle des Athoxyacetylens ( 28)c9', 981. Hier wird DMSO/festes NaOH/Katalysator angewendet.Ph-C-C H = CH-R Ph-C-C= CH2 Ph-C = C-CN Erwahnt sei noch die katalysierte Umsetzung von Phenylacetonitril mit CC1+ die ( 2 9 ) liefert[991.…”