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1.
Chem Commun (Camb) ; 56(77): 11445-11448, 2020 Sep 29.
Article in English | MEDLINE | ID: mdl-32852011

ABSTRACT

We report the first examples of radical cation Smiles rearrangements. A series of aryloxy alkylamines underwent spontaneous reaction, with the amino group displacing the ipso-alkoxy group through substitution, at ambient temperature and under photoactivation by visible light in the presence of an acridinium catalyst (5 mol%). The study was extended to 3-(2-methoxyphenyl)propan-1-amine derivatives, which lack an appropriate ipso leaving group. Here, efficient cyclisations resulted in displacement of the methoxy group and formation of tetrahydroquinolines.

2.
Angew Chem Int Ed Engl ; 59(17): 6740-6744, 2020 04 20.
Article in English | MEDLINE | ID: mdl-31943599

ABSTRACT

A scalable metal-, azide-, and halogen-free method for the synthesis of substituted 1,2,3-triazoles has been developed. The reaction proceeds through a 3-component coupling of α-ketoacetals, tosyl hydrazide, and a primary amine. The reaction shows outstanding functional-group tolerance with respect to both the α-ketoacetal and amine coupling partners, providing access to 4-, 1,4-, 1,5-, and 1,4,5-substituted triazoles in excellent yield. This robust method results in densely functionalised 1,2,3-triazoles that remain challenging to prepare by azide-alkyne cycloaddition (AAC, CuAAC, RuAAC) methods and can be scaled in either batch or flow reactors. Methods for the chemoselective reaction of either aliphatic amines or anilines are also described, revealing some of the potential of this novel and highly versatile transformation.

3.
Org Biomol Chem ; 17(34): 7943-7955, 2019 08 28.
Article in English | MEDLINE | ID: mdl-31429459

ABSTRACT

This paper describes the development, optimisation and exemplification of a copper-catalysed C-H functionalisation to form pharmaceutically relevant 2-aminobenzimidazoles from aryl-guanidines. High throughput screening was used as a tool to identify a catalytically active copper source, DoE was used for reaction optimisation and a range of aryl-guanidines were prepared and exposed to the optimum conditions to afford a range of 2-aminobenzimidazoles in moderate to good yields. The methodology has been applied to the synthesis of Emedastine, a marketed anti-histamine pharmaceutical compound, with the key cyclisation step performed on a gram-scale.

4.
Chemistry ; 21(26): 9535-43, 2015 Jun 22.
Article in English | MEDLINE | ID: mdl-26012874

ABSTRACT

Due to the discovery of RNAi, oligonucleotides (oligos) have re-emerged as a major pharmaceutical target that may soon be required in ton quantities. However, it is questionable whether solid-phase oligo synthesis (SPOS) methods can provide a scalable synthesis. Liquid-phase oligo synthesis (LPOS) is intrinsically scalable and amenable to standard industrial batch synthesis techniques. However, most reported LPOS strategies rely upon at least one precipitation per chain extension cycle to separate the growing oligonucleotide from reaction debris. Precipitation can be difficult to develop and control on an industrial scale and, because many precipitations would be required to prepare a therapeutic oligonucleotide, we contend that this approach is not viable for large-scale industrial preparation. We are developing an LPOS synthetic strategy for 2'-methyl RNA phosphorothioate that is more amenable to standard batch production techniques, using organic solvent nanofiltration (OSN) as the critical scalable separation technology. We report the first LPOS-OSN preparation of a 2'-Me RNA phosphorothioate 9-mer, using commercial phosphoramidite monomers, and monitoring all reactions by HPLC, (31)P NMR spectroscopy and MS.


Subject(s)
Oligonucleotides/chemistry , Organophosphorus Compounds/chemistry , RNA/chemical synthesis , Chromatography, High Pressure Liquid , Magnetic Resonance Spectroscopy , Organic Chemicals , RNA/chemistry , Solid-Phase Synthesis Techniques , Solvents/chemistry
5.
Congenit Heart Dis ; 9(1): 45-53, 2014.
Article in English | MEDLINE | ID: mdl-23648140

ABSTRACT

OBJECTIVE: To examine the knowledge and attitudes of anesthesia providers in relation to the care of adult congenital heart disease (ACHD) patients presenting for noncardiac surgery. DESIGN/SETTING: A novel survey was designed and administered to 168 anesthesiologists across a single academic department in a range of practice environments. INTERVENTIONS: None. OUTCOME MEASURES: Survey responses, including true/false, multiple choice, and Likert scale questions. RESULTS: A total of 118 anesthesiologists (response rate = 70%) completed the survey. Knowledge scores ranged from 0 to 19 (median [interquartile range] = 7 [5-13]) out of a possible maximum of 20. Total knowledge scores differed significantly by fellowship background (P = .004), with higher scores in those with cardiac (11 [7-15], P = .005) and pediatric (12 [6-15], P = .001) fellowship training, but not in those with critical care, obstetric, regional, or pain management training. Scores also differed by frequency of providing care for cardiopulmonary bypass cases and frequency of providing care for patients under 2 years of age (P < .001 for both), but not by gender or years removed from residency. Respondents reported only moderate levels of comfort with a range of questions about providing perioperative or obstetric care to ACHD patients, with decreasing levels of comfort reported in patients with more complex lesions. CONCLUSIONS: Within the context of the limitations of a single-institution survey design, the low levels of knowledge and comfort we observed suggest that providers may benefit from improved training and protocols for ensuring adequate preparedness for the care of ACHD patients.


Subject(s)
Anesthesia Department, Hospital , Anesthesia/methods , Attitude of Health Personnel , Health Knowledge, Attitudes, Practice , Heart Defects, Congenital/complications , Physicians/psychology , Adult , Age Factors , Anesthesia/adverse effects , Anesthesiology/education , Education, Medical, Graduate , Educational Status , Health Care Surveys , Heart Defects, Congenital/physiopathology , Humans , Risk Assessment , Risk Factors , Specialization , Surveys and Questionnaires , Workforce
6.
Chem Commun (Camb) ; (37): 4735-7, 2005 Oct 07.
Article in English | MEDLINE | ID: mdl-16175309

ABSTRACT

A one-pot sequence of amine deprotection, intramolecular C=N bond formation and subsequent asymmetric reduction may be promoted by a ruthenium catalyst.

7.
Org Lett ; 5(22): 4227-30, 2003 Oct 30.
Article in English | MEDLINE | ID: mdl-14572291

ABSTRACT

[reaction: see text]. Cyclic amines may be prepared via a sequence of deprotection followed by intramolecular reductive amination of t-Boc-protected amino ketones under asymmetric transfer hydrogenation conditions. In cases where the corresponding imine reaction proceeds with high enantioselectivity, this is reflected in the one-step process.

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