102592-55-2Relevant academic research and scientific papers
Rhodium-catalyzed oxygenative [2 + 2] cycloaddition of terminal alkynes and imines for the synthesis of β-lactams
Kim, Insu,Roh, Sang Weon,Lee, Dong Gil,Lee, Chulbom
, p. 2482 - 2485 (2014)
A rhodium-catalyzed oxygenative [2 + 2] cycloaddition of terminal alkynes and imines has been developed, which gives β-lactams as products with high trans diastereoselectivity. In the presence of a Rh(I) catalyst and 4-picoline N-oxide, a terminal alkyne is converted to a rhodium ketene species via oxidation of a vinylidene complex and subsequently undergoes a [2 + 2] cycloaddition with an imine to give rise to the 2-azetidinone ring system. Mechanistic studies suggest that the reaction proceeds through a metalloketene rather than free ketene intermediate. The new method taking advantage of catalytic generation of a ketene species directly from a terminal alkyne provides a novel and efficient entry to the Staudinger synthesis of β-lactams under mild conditions.
Combination of Enabling Technologies to Improve and Describe the Stereoselectivity of Wolff-Staudinger Cascade Reaction
Musio,Mariani,?liwiński,Kabeshov,Odajima,Ley
supporting information, p. 3515 - 3526 (2016/10/18)
A new, single-mode bench-top resonator was evaluated for the microwave-assisted flow generation of primary ketenes by thermal decomposition of α-diazoketones at high temperature. A number of amides and β-lactams were obtained by ketene generation in situ and reaction with amines and imines, respectively, in good to excellent yields. The preferential formation of trans-configured β-lactams was observed during the [2+2] Staudinger cycloaddition of a range of ketenes with different imines under controlled reaction conditions. Some insights into the mechanism of this reaction at high temperature are reported, and a new web-based molecular viewer, which takes advantage from Augmented Reality (AR) technology, is also described for a faster interpretation of computed data.
Stereoselective synthesis of trans β-lactams via palladium/N- heterocyclic carbene-catalyzed carbonylative [2+2] cycloaddition
Xie, Pan,Qian, Bo,Huang, Hanmin,Xia, Chungu
supporting information; experimental part, p. 1613 - 1616 (2012/04/17)
The carbonylative [2+2] cycloaddition of benzyl chlorides and allyl derivatives with imines and CO for synthesis of β-lactam is effectively catalyzed by palladium/N-heterocyclic carbene complex. The desired β-lactam could be obtained in good to excellent yields (61-96%) with excellent regioselectivities (trans/cis > 95:5) and chiral lactams could be obtained with moderate diastereoselectivities. The KIE experimental studies have revealed that the C-H cleavage is most likely to be the rate-limiting step for the carbonylative cycloaddition.
