Stepwise Skeletal Rearrangement:  Four-Membered-Ring CyclizationviaC−H Bond Cleavage and C−C Bond Cleavage of a Four-Membered Ring by Rhodium(I)

1996 ◽  
Vol 15 (3) ◽  
pp. 895-897 ◽  
Author(s):  
Chul-Ho Jun
2014 ◽  
Vol 50 (71) ◽  
pp. 10291-10294 ◽  
Author(s):  
Youhei Takeda ◽  
Masato Okazaki ◽  
Satoshi Minakata

An oxidative skeletal rearrangement of 1,1′-binaphthalene-2,2′-diamines (BINAMs) that involves the cleavage of a strong C–C single bond of the binaphthalene unit and the nitrogen migration has been discovered.


1999 ◽  
Vol 54 (6) ◽  
pp. 725-733 ◽  
Author(s):  
M. Fernanda N. N. Carvalho ◽  
Armando J. L. Pombeiro ◽  
Gabriele Wagner ◽  
Bjørn Pedersen ◽  
Rudolf Herrmann

Platinum(II) catalyzes the isomerization of camphor sulfonamide diynes in a cascade reaction involving annulation of a five-membered ring to the camphor skeleton, ring-enlargement by C-C bond cleavage, reduction of sulfur(VI) to sulfur(IV), and oxidation of a hydroxy group to a ketone. The reactions of the diynes with other transition metal compounds were also studied. Copper, gold and rhenium give final products similar to those obtained with simple Brønsted acids or halogens, mainly by annulation o f a five-membered ring to the camphor moiety, accompanied by reduction of a sulfonamide to a sulfinamide group, but lacking the ring-enlargement step. Palladium(II) occupies an intermediate position as both types o f products are obtained. The reaction mechanism and intermediates are discussed


Synlett ◽  
2018 ◽  
Vol 30 (04) ◽  
pp. 393-396 ◽  
Author(s):  
Shinya Gima ◽  
Keigo Shiga ◽  
Masahiro Terada ◽  
Itaru Nakamura

We successfully extended our gold-catalyzed skeletal rearrangement reaction of O-propargylic oximes through C=N bond cleavage to include substrates having an ester group on the oxime moiety, affording the corresponding 2-isoxazolines having an alkoxycarbonylmethylene group at the 4-position in good to high yields. Our mechanistic studies indicated that the transfer of the alkoxycarbonylmethylene group proceeded in an intermolecular manner, confirming that the reaction proceeds through cyclization followed by intermolecular transfer of the alkoxycarbonylmethylene group.


2011 ◽  
Vol 14 (1) ◽  
pp. 206-209 ◽  
Author(s):  
Itaru Nakamura ◽  
Tomoki Iwata ◽  
Dong Zhang ◽  
Masahiro Terada

2019 ◽  
Vol 75 (4) ◽  
pp. 398-401
Author(s):  
Detlef Selent ◽  
Anke Spannenberg ◽  
Christoph Kubis ◽  
Armin Börner

A hydroxy phosphonite was found to be unstable during the catalyst preformation routine applied towards a rhodium olefin hydroformylation catalyst. C—P bond cleavage occurred when the phosphonite was reacted with [(acac)Rh(1,5-COD)] (acac is acetyl acetate and 1,5-COD is cycloocta-1,5-diene) at 80 °C and 20 bar of CO/H2. As a result, a nearly planar six-membered ring structure consisting of two rhodium(I) cations and two bridging phosphorous acid diester anions was formed, namely bis[μ-(4,8-di-tert-butyl-2,10-dimethoxydibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]-1:2κ2 P:O;1:2κ2 O:P-bis{[6-([1,1′-biphenyl]-2-yloxy)-4,8-di-tert-butyl-2,10-dimethoxydibenzo[d,f][1,3,2]dioxaphosphepine-κP]carbonylrhodium(I)} toluene tetrasolvate, [Rh2(C22H28O5P)2(C34H37O5P)2(CO)2]·4C7H8. Further coordination of phosphite and of carbonyl groups resulted in 16-electron rhodium centres.


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