113472-45-0Relevant articles and documents
Bioinspired Diversification Approach Toward the Total Synthesis of Lycodine-Type Alkaloids
Haley, Hannah M. S.,Payer, Stefan E.,Papidocha, Sven M.,Clemens, Simon,Nyenhuis, Jonathan,Sarpong, Richmond
, p. 4732 - 4740 (2021)
Nitrogen heterocycles (azacycles) are common structural motifs in numerous pharmaceuticals, agrochemicals, and natural products. Many powerful methods have been developed and continue to be advanced for the selective installation and modification of nitrogen heterocycles through C-H functionalization and C-C cleavage approaches, revealing new strategies for the synthesis of targets containing these structural entities. Here, we report the first total syntheses of the lycodine-type Lycopodium alkaloids casuarinine H, lycoplatyrine B, lycoplatyrine A, and lycopladine F as well as the total synthesis of 8,15-dihydrohuperzine A through bioinspired late-stage diversification of a readily accessible common precursor, N-desmethyl-β-obscurine. Key steps in the syntheses include oxidative C-C bond cleavage of a piperidine ring in the core structure of the obscurine intermediate and site-selective C-H borylation of a pyridine nucleus to enable cross-coupling reactions.
C-H/C-C Functionalization Approach to N-Fused Heterocycles from Saturated Azacycles
Ham, Jin Su,Park, Bohyun,Son, Mina,Roque, Jose B.,Jurczyk, Justin,Yeung, Charles S.,Baik, Mu-Hyun,Sarpong, Richmond
, p. 13041 - 13050 (2020/09/01)
Herein we report the synthesis of substituted indolizidines and related N-fused bicycles from simple saturated cyclic amines through sequential C-H and C-C bond functionalizations. Inspired by the Norrish-Yang Type II reaction, C-H functionalization of azacycles is achieved by forming α-hydroxy-β-lactams from precursor α-ketoamide derivatives under mild, visible light conditions. Selective cleavage of the distal C(sp2)-C(sp3) bond in α-hydroxy-β-lactams using a Rh-complex leads to α-acyl intermediates which undergo sequential Rh-catalyzed decarbonylation, 1,4-addition to an electrophile, and aldol cyclization, to afford N-fused bicycles including indolizidines. Computational studies provide mechanistic insight into the observed positional selectivity of C-C cleavage, which depends strongly on the groups bound to Rh trans to the phosphine ligand.
Photocyclisation of Phenylglyoxylamides as Inclusion Complexes with an Optically Active Host Derived from Tartaric Acid: Delicate Dependence on the Substituent of the Host and Glyoxylamide
Toda, Fumio,Miyamoto, Hisakazu,Matsukawa, Rikiya
, p. 1461 - 1462 (2007/10/02)
Optically active β-lactams and/or oxazolidinones have been obtained selectively by photoirradiation of a 1:2 inclusion complex of phenylglyoxylamide with an optically active host derived from tartaric acid.Delicate selectivity which is dependent on substituents in the phenylglyoxylamide and the host is described.
HIGHLY SELECTIVE PHOTOREACTIONS OF α-OXOAMIDES AND α-TROPOLONE ALKYL ETHERS IN CRYSTALLINE INCLUSION COMPLEXES
Toda, Fumio,Tanaka, Koichi,Yagi, Minoru
, p. 1495 - 1502 (2007/10/02)
Control of photocyclization of three α-oxoamides in crystalline inclusion complexes with three kinds of host compounds was studied.In all cases, β-lactams were obtained exclusively.In two cases, cis-β-lactams were formed selectively.By an enantioselective