A Kinetic Study of the ortho-Claisen Rearrangement¹

Ruthenium‐Catalyzed O‐Allylation of Phenols from Allylic Chlorides via Cationic [Cp*(η3‐allyl)(MeCN)RuX][PF6] Complexes

“…The isomeric 3-chloro-1-butene MeCH(Cl) CH ¼ CH 2 , and crotyl chloride MeCH ¼ CHCH 2 Cl both react with phenol and K 2 CO 3 in acetone at reflux to afford the corresponding branched and linear phenyl ethers MeCH(OPh)CH ¼ CH 2 , 5a, and MeCH ¼ CHCH 2 OPh, 6a, respectively. [18] We have verified that the reaction is sluggish at room temperature, especially with respect to 3-chloro-1-butene. Under our catalytic conditions (vide supra), the reaction of crotyl chloride led to a mixture of 5a and 6a in a 5 : 1 molar ratio as determined by 1 H NMR spectroscopy (Scheme 4).…”

Ruthenium(IV)‐Catalyzed Isomerization of the CC Bond of O‐Allylic Substrates: A Theoretical and Experimental Study

“…Organic solvents were dried by standard methods and distilled under nitrogen before use. All reagents were obtained from commercial suppliers and used without further purification with the exception of [{Ru(h 3 :h 3 -C 10 H 16 )A C H T U N G T R E N N U N G (m-Cl)Cl} 2 ] (1), [37] allyl 2-chlorophenyl ether (3 b), [38] allyl 3-chlorophenyl ether (3 c), [39] allyl 4-chlorophenyl ether (3 d), [40] allyl 4-formylphenyl ether (3 e), [41] 4-(N-acetylamino)phenyl allyl ether (3 f), [40] allyl 2-methylphenyl ether (3 g), [42] allyl 4-methylphenyl ether (3H), [42] 6-allyloxyquinoline (3 k), [43] 2,2'-bisA C H T U N G T R E N N U N G (allyloxy)-1,1'-binaphthalene (3 l), [44] 2-acetylphenyl allyl ether (3 m), [45] 2-allyloxybenzophenone (3 n), [46] 2-cyanophenyl allyl ether (3 o), [47] allyl ethyl ether (3 p), [48] 3-(allyloxypropyl)benzene (3 s), [49] and allyl diphenylmethyl ether (3 t), [50] which were prepared by following the methods reported in the literature. GC measurements were made with a Hewlett-Packard HP6890 Preparation of allyl 3-(diethylamino)phenyl ether (3 j): K 2 CO 3 (11.0 g, 80 mmol) was added to a stirred solution of 3-(diethylamino)phenol (3.41 g, 20 mmol) in acetone (100 mL) at room temperature, and the resulting mixture heated to reflux for 1 h. Allyl bromide (1.76 mL, 22 mmol) was then added, and reflux continued for additional 4 h. After this time, the reaction mixture was cooled to room temperature, filtered, and the filtrate evaporated to dryness.…”

Synthesis of Benzaldehyde‐Functionalized Glycans: A Novel Approach Towards Glyco‐SAMs as a Tool for Surface Plasmon Resonance Studies

“…[40] The required simple aldehyde linker 21 was obtained by nucleophilic substitution of allyl bromide with 4-hydroxybenzaldehyde (19) and acetalization with trimethyl orthoformate (TMoF) in nearly quantitative yield (Scheme 5). [41,42] Unlike the widely used ring-closing metathesis procedure, cross metathesis gives the desired compounds along with several byproducts. [43] Cross metathesis has only recently attracted more attention in carbohydrate chemistry because novel and more active catalysts have only just become available.…”