65476-99-5

Upstream product

• 109925-94-2 5-Methyl-3-phenyl-6-trimethylsilanyloxy-5,6-dihydro-4H-[1,2]oxazine 
• 117341-61-4 6-Methoxy-5-methyl-3-phenyl-6H-1,2-oxazine 
• 117341-58-9 5,6-Dihydro-6-methoxy-5-methylene-3-phenyl-4H-1,2-oxazine 
• 73475-33-9 2-methyl-4-phenylbutanenitrile 
• 103-63-9 1-phenyl-2-bromoethane 
• 768-56-9 4-Phenylbut-1-ene 
• 61012-64-4 1-tert-butyl-N,1,1-trimethylsilanamine 

Relevant academic research and scientific papers

Fast Titanium-Catalyzed Hydroaminomethylation of Alkenes and the Formal Conversion of Methylamine

The scientific interest in catalytic hydroaminoalkylation reactions of alkenes has vastly increased over the past decade, but these reactions have struggled to become a viable option for general laboratory or industrial use because of reaction times of several days. The titanium-based catalytic system introduced in this work not only reduces the reaction time by several orders of magnitude, into the range of minutes, but the catalyst is also demonstrated to be easily available from common starting materials, at a cost of approximately 1 € per millimole of catalyst. We were also able to formally perform C?H activation of methylamine and achieve coupling to a broad variety of alkenes, through silyl protection of the amine and simple deprotection by water.

Anodic benzylic C(sp3)-H amination: Unified access to pyrrolidines and piperidines

An electrochemical aliphatic C-H amination strategy was developed to access the important heterocyclic motifs of pyrrolidines and piperidines within a uniform reaction protocol. The mechanism of this unprecedented C-H amination strategy involves anodic C-H activation to generate a benzylic cation, which is efficiently trapped by a nitrogen nucleophile. The applicability of the process is demonstrated for 40 examples comprising both 5- and 6-membered ring formations.

An Iodine-Catalyzed Hofmann-L?ffler Reaction

Iodine reagents have been identified as economically and ecologically benign alternatives to transition metals, although their application as molecular catalysts in challenging C-H oxidation reactions has remained elusive. An attractive iodine oxidation catalysis is now shown to promote the convenient conversion of carbon-hydrogen bonds into carbon-nitrogen bonds with unprecedented complete selectivity. The reaction proceeds by two interlocked catalytic cycles comprising a radical chain reaction, which is initiated by visible light as energy source. This unorthodox synthetic strategy for the direct oxidative amination of alkyl groups has no biosynthetic precedence and provides an efficient and straightforward access to a general class of saturated nitrogenated heterocycles.

Reactions of 6--5,6-dihydro-4H-1,2-oxazines

1,2-Oxazine 1 was converted into an unusual condensation product 5 by treatment with tetra-n-butylammonium fluoride.The hydrogenolysis of 1 with Pd/C as catalyst provided the expected primary amine 9, whereas the same reaction with the ethoxycarbonyl-substituted 1,2-oxazine 2 as starting material gave the 4-methylproline derivative 10 after N-protection.Deprotonation at C-4 of 1 required rather harsh conditions but cleanly afforded the corresponding lithiated intermediate 11.Treatment of 11 with electrophiles provided the C-4-substituted derivatives 12-16 in good to moderate yield, but generally with very high diastereoselectivity.The overall substitution process preferentially occurs with retention of configuration which is explained by assuming ion pair structure B for intermediate 11. - Key Words: 1,2-Oxazines, bis(trimethylsilyl)amino-substituted / Hydrogenolysis / Deprotonation / Alkylation / Deuteration

Model Studies of the Reduction of 3-Phenyl-6H-1,2-oxazines, Chemo- and Stereoselectivity: Synthesis of Amino Alcohols, Amino Acids, and Related Compounds

While palladium-catalyzed hydrogenation of 3-phenyl-6H-1,2-oxazine 1 produces primary amine 5 in a nitrogen-transposition reaction, the reductions of the related 1,2-oxazines 2, 10, and the 1,2-oxazin-6-one 3 afford the expected amino alcohols 4, 11, and the γ-amino acid 6, respectively, with low diastereoselectivities.In the presence of acetic acid 3 is reductively converted into γ-keto carboxylic acid 9 and 1 into the γ-lactam derivative 12 probably by a ring contraction to a nitrone intermediate.Raney nickel as the catalyst is able to transform 1,2-oxazine 7 bearing an exo-methylene unit into 3,4-dihydro-2H-pyrrole 13.The reaction of 6H-1,2-oxazine 1 with aluminium amalgam produces pyrrole 14 in moderate yield.Treatment of 1 with sodium in 2-propanol brings about its transformation into pyrrolidine derivative 15 together with pyrrole 14 and amino alcohol 4 as minor products.The chemoselectivity and stereoselectivity of these reductions are discussed including mechanistic proposals for the multistep processes involved. Key Words: 1,2-Oxazines / Hydrogenation, catalytic / Amino alcohols / γ-Amino acids / Pyrroles / γ-Lactams

Reductive Transformations of 5,6-Dihydro-4H-1,2-oxazines: Synthesis of 4-Hydroxy Ketoximes, N-Hydroxypyrrolidine Derivatives, and Other Nitrogen-Containing Compounds

6-Siloxy-substituted 1,2-oxazines 1 are transformed into 4-hydroxy ketoximes 2 by reduction with NaBH4 in ethanol.Reductive Beckmann rearrangement converts the oxime 2a into the 1,4-amino alcohol 7.Diisobutylaluminum hydride (DIBAH) induces a novel reductive ring contraction of 1 to provide either N-hydroxypyrrolidine derivatives 8 or nitrones 9.Other 1,2-oxazines lacking the 6-siloxy substituent are also studied under these reaction conditions.Catalytic hydrogenolysis either gives the acyclic amine 16 or it stops at the stage of the proline derivative 21.Mechanistic features of these synthetically valuable transfomations are discussed.