Reduction of conjugate double bonds with trichlorosilane

2000 ◽  
Vol 78 (11) ◽  
pp. 1396-1398 ◽  
Author(s):  
Moni Chauhan ◽  
Philip Boudjouk
Keyword(s):  
Double Bond ◽  
Carbonyl Compounds ◽  
Double Bonds ◽  
Cyclic Ketones ◽  
Unsaturated Esters ◽  
Mild Conditions ◽  
Carbon Double Bond

A variety of α,β-unsaturated esters and cyclic ketones underwent smooth reduction of the carbon–carbon double bond with a combination of inexpensive and readily available trichlorosilane and CoCl2. The reactions are performed under very mild conditions and products are obtained in high yields.Key words: reduction, carbonyl compounds, trichlorosilane, ketones, chemoselectivity.

Neodymium-Promoted Highly Selective Carbon–Carbon Double Bond Formation of Ketones with Allyl Halides in the Presence of Diethyl Phosphite

Synthesis ◽  
2020 ◽  
Vol 52 (22) ◽  
pp. 3446-3451
Author(s):  
Songlin Zhang ◽  
Dengbing Xie ◽  
Yiqiong Wang ◽  
Bo Yang
Keyword(s):  
Double Bond ◽  
Bond Formation ◽  
Point Of View ◽  
Diethyl Phosphite ◽  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions ◽  
Carbon Double Bond ◽  
Allyl Halides ◽  
First Time

The carbon–carbon double bond formation via neodymium-mediated Barbier-type reaction of ketones and allyl halides in the presence of diethyl phosphite is reported for the first time. The reaction is highly α-regioselective and was conveniently carried out under mild conditions in a one-pot fashion. From a synthetic point of view, a series of conjugated alkenes were obtained in moderate to good yields in this one-pot reaction with feasible reaction conditions.

Radical clocks as probes of 1,4-biradical intermediates in the photochemical cycloaddition reactions of 2-cyclopentenone with alkenes

1990 ◽  
Vol 68 (9) ◽  
pp. 1590-1597 ◽  
Author(s):  
Andreas Rudolph ◽  
Alan C. Weedon
Keyword(s):  
Double Bond ◽  
Rate Constant ◽  
Photochemical Reaction ◽  
Cycloaddition Reactions ◽  
Double Bonds ◽  
Radical Clocks ◽  
Carbon Double Bond

The products of the photochemical reaction of 2-cyclopentenone with 1,6-heptadiene and with vinylcyclopropane have been examined. With 1,6-heptadiene the products were cyclobutanes, which arise from 2 + 2 photocycloaddition between the cyclopentenone carbon–carbon double bond and one of the two terminal double bonds of the heptadiene. The 1,4-biradical that is an intermediate in this reaction contains a derivative of a 1-hexenyl radical; no products derived from cyclization of this intermediate to a cyclopentylmethyl radical were observed. With vinylcyclopropane some of the products isolated also arose from 2 + 2 photocycloaddition; in addition, comparable quantities of products resulting from rearrangement of the intermediate 1,4-biradical were obtained. In this case the initially produced intermediate 1,4-biradical contains a cyclopropylmethyl radical that can rearrange to a homoallylic radical; the products isolated were derived from intramolecular disproportionation in the new 1,7-biradical containing the homoallylic radical. The rate constant for the rearrangement of the cyclopropylmethyl radical to the homoallylic radical is known and was used as a clock to estimate the lifetime of the initially produced 1,4-biradical. The value estimated is of the order of 50 ns. The structures of the products indicate that the initial bonding between the excited cyclopentenone and vinylcyclopropane takes place at both the α-position and the β-position of the enone and not exclusively at the α-position as a recent report claims. Keywords: enone photocycloaddition, 1,4-biradicals, radical clocks.

Study of the Reaction of Buna Rubbers with Aliphatic Thiols

1949 ◽  
Vol 22 (1) ◽  
pp. 148-154
Author(s):  
G. E. Serniuk ◽  
F. W. Banes ◽  
M. W. Swaney
Keyword(s):  
Double Bond ◽  
Chain Length ◽  
Thioglycolic Acid ◽  
Benzene Solution ◽  
Polymer Chains ◽  
Double Bonds ◽  
Mild Conditions ◽  
Acid Addition ◽  
Aliphatic Thiols

Abstract Thioglycolic acid added exothermally to butadiene polymers and copolymers in benzene solution under mild conditions to give apparent double-bond saturation values of 38 to 47 per cent. When the same polymers reacted with aliphatic thiols of C2 to C16 chain length, in mass or latex reactions, saturation values were obtained which were in accord with those found by thioglycolic acid addition. It is suggested that the double bonds in butadiene polymers and copolymers which were readily saturated by the above thiols are predominately those present in the polymer chains as vinyl side groups.

Direct Preparation of N-(Alk-1-en-1-yl)carbamates from Cyclic Ketones and Unsubstituted Carbamates

2002 ◽  
Vol 67 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Philippe Dupau ◽  
Anne-Emmanuelle Hay ◽  
Célia Alameda Angulo ◽  
Pierre H. Dixneuf ◽  
Christian Bruneau
Keyword(s):  
Double Bond ◽  
Sulfonic Acid ◽  
Catalytic Amount ◽  
Cyclic Ketones ◽  
Carbon Double Bond ◽  
Direct Preparation

N-(Alk-1-en-1-yl)carbamates bearing an endocyclic carbon-carbon double bond have been prepared by the reaction of unsubstituted carbamates with tetrahydronaphthalen-2-one and chroman-2-one derivatives in the presence of a catalytic amount of 4-methylbenzene-1-sulfonic acid.

New agents for the selective reduction of the carbon-carbon double bond of .alpha.,.beta.-unsaturated carbonyl compounds

1991 ◽  
Vol 56 (23) ◽  
pp. 6720-6722 ◽  
Author(s):  
Yutaka Nishiyama ◽  
Masanori Yoshida ◽  
Shigeo Ohkawa ◽  
Sawako Hamanaka
Keyword(s):  
Double Bond ◽  
Carbonyl Compounds ◽  
Selective Reduction ◽  
New Agents ◽  
Carbon Double Bond ◽  
Alpha Beta
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