37676-90-7Relevant academic research and scientific papers
Evaluation of an aza-Michael approach for the synthesis of 3,3-dimethyl-2-aminocyclobutane-1-carboxylic acid
Charnay-Pouget, Florence,Frank, Michael,Baltaze, Jean-Pierre,Pereira, Elisabeth,Aitken, David J.
scheme or table, p. 80 - 93 (2012/03/11)
The aza-Michael addition reaction of a dibenzylic amide anion with t-butyl 3,3-dimethylcyclobutene-1-carboxylate was investigated as a route to the title compound a cyclic β-amino acid. In analogy with the known 5- and 6-membered ring homologues,the addition reaction proceeds smoothly,but with moderate diastereomeric and enantiomeric selectivities. The trans isomer of the title β-amino acid was obtained,for the first time,with a modest enantiomeric excess. ARKAT-USA, Inc.
The Kinetics and Mechanism of Ring Opening of Radicals containing the Cyclobutylcarbinyl System
Beckwith, Athelstan L. J.,Moad, Graeme
, p. 1083 - 1092 (2007/10/02)
The kinetic parameters of β-fission of radicals containing the cyclobutylcarbinyl system have been determined by analysis of the mixtures obtained when suitable chloro-compounds are treated with tributylstannane.Under these conditions ring opening is irreversible and in the rigid bicyclic system (4) is under stereoelectronic control.For ring opening of cyclobutylcarbinyl radical (8) kf = 4.3 x 103 s-1 at 60 deg C, and the best values of the activation parameters appear to be ΔH(excit.) = 12.2 kcal mol-1 and ΔS(excit.) = -7.4 cal mol-1 K-1.Monocyclic systems undergo preferential fission of the more substituted βγ-bond.Methyl substituents at the α-, β-, or δ-positions have little effect but γ-substitution strongly enhances the rate of ring opening.The transition state is reactant-like and has a similar disposition of centres to that (1) for homolytic addition.
