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Selected Works

Ram S. Mohan

Articles 1 - 30 of 52

Full-Text Articles in Chemistry

Bismuth(Iii) Bromide Catalyzed Synthesis Of Polyhydroquinoline Derivatives Via The Hantzsch Reaction, Joshua Yoo, Thomas Laughlin, Joseph Krob, Ram Mohan Apr 2015

Bismuth(Iii) Bromide Catalyzed Synthesis Of Polyhydroquinoline Derivatives Via The Hantzsch Reaction, Joshua Yoo, Thomas Laughlin, Joseph Krob, Ram Mohan

Ram S. Mohan

Bismuth(III) bromide is an efficient catalyst for the one-pot multicomponent synthesis of polyhydroquinolines via the Hantzsch reaction. The mild reaction conditions, short reaction times, high yields, and the remarkably low toxicity of bismuth compounds make this method especially attractive.

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Isolation Of Thymol From Carom Seeds, Ram Mohan, Leonard Onsen Mar 2015

Isolation Of Thymol From Carom Seeds, Ram Mohan, Leonard Onsen

Ram S. Mohan

A simple protocol for the isolation and characterization of thymol from Trachyspermum ammi, commonly known as Bishop’s weed or carom seed, is reported. Carom seeds are commonly used in Indian cooking as a digestive aid, to treat stomach pain, and for their carminative properties. The protocol, developed as an experiment for introductory organic chemistry laboratories, provides instruction in natural product isolation, chromatographic techniques, acid-base concepts and NMR spectroscopy.

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New Methods For Lewis Acid Catalyzed 1,4 Conjugate Addition Of Indole To Chalcones, Ram Mohan, Joseph Krob, '14, Nicholas Lazzara, '16 Apr 2014

New Methods For Lewis Acid Catalyzed 1,4 Conjugate Addition Of Indole To Chalcones, Ram Mohan, Joseph Krob, '14, Nicholas Lazzara, '16

Ram S. Mohan

No abstract provided.

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Additon Of A Grignard Reagent To Α,Β-Unsaturated Carbonyl Compounds: A Discovery-Oriented Laboratory Experiment For Sophomore Organic Chemistry, Ram Mohan, Meghan Gradle, '15 Apr 2014

Additon Of A Grignard Reagent To Α,Β-Unsaturated Carbonyl Compounds: A Discovery-Oriented Laboratory Experiment For Sophomore Organic Chemistry, Ram Mohan, Meghan Gradle, '15

Ram S. Mohan

No abstract provided.

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A Comparative Study On The Utility Of Metal Triflates As Catalysts For The Allyation Of Aromatic Acetals And Dioxolanes, Ram Mohan, Dohun Lee, Faculty Advisor, Brendan O'Donnell, '14, Justin Feng, '15 Apr 2014

A Comparative Study On The Utility Of Metal Triflates As Catalysts For The Allyation Of Aromatic Acetals And Dioxolanes, Ram Mohan, Dohun Lee, Faculty Advisor, Brendan O'Donnell, '14, Justin Feng, '15

Ram S. Mohan

No abstract provided.

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Iron (Iii) Tosylate Catalyzed Synthesis Of 3,4-Dihydropyrimidin-2(1h)-Ones/Thiones, Ram S. Mohan, Jacob T. Starcevich, Thomas J. Laughlin Dec 2012

Iron (Iii) Tosylate Catalyzed Synthesis Of 3,4-Dihydropyrimidin-2(1h)-Ones/Thiones, Ram S. Mohan, Jacob T. Starcevich, Thomas J. Laughlin

Ram S. Mohan

No abstract provided.

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Iron (Iii) Tosylate Catalyzed Synthesis Of Acylals (1,1-Diesters) From Aromatic Aldehydes, Ram Mohan, Anna Nord, '13 Apr 2012

Iron (Iii) Tosylate Catalyzed Synthesis Of Acylals (1,1-Diesters) From Aromatic Aldehydes, Ram Mohan, Anna Nord, '13

Ram S. Mohan

No abstract provided.

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Iron (Iii) Tosylate Catalyzed Synthesis Of Dihydropyrimidiones And Dihydropyrmidinothiones Via The Biginelli Reaction, Ram Mohan, Jacob Starcevich, '13, Thomas Laughlin, '14 Apr 2012

Iron (Iii) Tosylate Catalyzed Synthesis Of Dihydropyrimidiones And Dihydropyrmidinothiones Via The Biginelli Reaction, Ram Mohan, Jacob Starcevich, '13, Thomas Laughlin, '14

Ram S. Mohan

No abstract provided.

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Iron (Iii) Tosylate Catalyzed Synthesis Of Dihydrobenzopyrans, Ram Mohan, Stephen Whitfield, '14 Apr 2012

Iron (Iii) Tosylate Catalyzed Synthesis Of Dihydrobenzopyrans, Ram Mohan, Stephen Whitfield, '14

Ram S. Mohan

No abstract provided.

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Bismuth (Iii) Triflate Catalyzed Synthesis Of Homoallyl Allyl Ethers And Their Reactions, Ram Mohan, Brendan O'Donnell, '14 Apr 2012

Bismuth (Iii) Triflate Catalyzed Synthesis Of Homoallyl Allyl Ethers And Their Reactions, Ram Mohan, Brendan O'Donnell, '14

Ram S. Mohan

No abstract provided.

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Iron (Iii) Tosylate Catalyzed Acylation Of Alcohols And Phenols, Ram Mohan, Neil Baldwin, '13 Apr 2012

Iron (Iii) Tosylate Catalyzed Acylation Of Alcohols And Phenols, Ram Mohan, Neil Baldwin, '13

Ram S. Mohan

No abstract provided.

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Environmentally Friendly Organic Synthesis Using Bismuth(Iii) Compounds, Ram Mohan, Scott Krabbe Dec 2011

Environmentally Friendly Organic Synthesis Using Bismuth(Iii) Compounds, Ram Mohan, Scott Krabbe

Ram S. Mohan

Abstract With increasing environmental concerns, the need for environmentally friendly organic synthesis has gained increased importance. In this regard, bismuth (III) compounds are especially attractive as “green” reagents and catalysts for organic synthesis. Bismuth(III) compounds are remarkably nontoxic, relatively air and moisture stable, and easy to handle. The contributions from our laboratory in the last 5 years in the field of applications of bismuth(III) compounds as catalysts are presented.

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Iron(Iii) Tosylate Catalyzed Acylation Of Alcohols, Phenols, And Aldehydes, Ram S. Mohan, Neil J. Baldwin, Anna N. Nord, Brendan D. O’Donnell Dec 2011

Iron(Iii) Tosylate Catalyzed Acylation Of Alcohols, Phenols, And Aldehydes, Ram S. Mohan, Neil J. Baldwin, Anna N. Nord, Brendan D. O’Donnell

Ram S. Mohan

Iron(III) p-toluenesulfonate (tosylate) is an efficient catalyst for acetylation of alcohols, phenols, and aldehydes. The acetylation of 1° and 2° alcohols, diols, and phenols proceeded smoothly with 2.0 mol % of catalyst. However, the reaction worked well with only a few 3° alcohols. The methodology was also applicable to the synthesis of a few benzoate esters but required the use of 5.0 mol % catalyst. Aldehydes could also be converted into the corresponding 1,1-diesters (acylals) under the reaction conditions. Iron(III) tosylate is an inexpensive, and easy to handle, commercially available catalyst.

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Applications Of Bismuth(Iii) Compounds In Organic Synthesis, Ram Mohan, Jason Bothwell, Scott Krabbe Aug 2011

Applications Of Bismuth(Iii) Compounds In Organic Synthesis, Ram Mohan, Jason Bothwell, Scott Krabbe

Ram S. Mohan

This review article summarizes the applications of bismuth(III) compounds in organic synthesis since 2002. Although there are an increasing number of reports on applications of bismuth(III) salts in polymerization reactions, and their importance is acknowledged, they are not included in this review. This review is largely organized by the reaction type although some reactions can clearly be placed in multiple sections. While every effort has been made to include all relevant reports in this field, any omission is inadvertent and we apologize in advance for the same (358 references).

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A Mild Method For The Deprotection Of Tetrahydropyranyl (Thp) Ethers Catalyzed By Iron(Iii) Tosylate, Ram Mohan, Matthew Bockman, Veronica Angeles, Julia Martino, Purav Vagadia Dec 2010

A Mild Method For The Deprotection Of Tetrahydropyranyl (Thp) Ethers Catalyzed By Iron(Iii) Tosylate, Ram Mohan, Matthew Bockman, Veronica Angeles, Julia Martino, Purav Vagadia

Ram S. Mohan

A mild method for the deprotection of THP ethers catalyzed by iron(III) tosylate (2.0 mol %) in CH3OH has been developed. Iron(III) tosylate, Fe(OTs)3.6H2O, is a commercially available solid that is inexpensive, noncorrosive, and easy to handle. The room temperature reaction conditions make this method attractive for deprotection of a range of THP ethers.

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Bismuth(Iii) Triflate Catalyzed Allylation Of Cyclic Acetals And Dithianes Followed By In Situ Derivatization To Generate Highly Functionalized Esters, Ram Mohan, Scott Krabbe, Matthew Spafford Dec 2009

Bismuth(Iii) Triflate Catalyzed Allylation Of Cyclic Acetals And Dithianes Followed By In Situ Derivatization To Generate Highly Functionalized Esters, Ram Mohan, Scott Krabbe, Matthew Spafford

Ram S. Mohan

No abstract provided.

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Bismuth Compounds In Organic Synthesis: Synthesis Of Dioxanes, Dioxepines, And Dioxolanes Catalyzed By Bismuth(Iii) Triflate, Ram Mohan, Daniel Podgorski, Scott Krabbe, Long Le, Paul Sierszulski Dec 2009

Bismuth Compounds In Organic Synthesis: Synthesis Of Dioxanes, Dioxepines, And Dioxolanes Catalyzed By Bismuth(Iii) Triflate, Ram Mohan, Daniel Podgorski, Scott Krabbe, Long Le, Paul Sierszulski

Ram S. Mohan

A simple method for the synthesis of l,3-dioxolanes from carbonyl compounds has been developed using l,2-bis(trimethylsilyloxy) ethane in the presence of bismuth (III) triflate as a catalyst. The bismuth(III) triflate catalyzed synthesis of a range of dioxanes and dioxepines has also been developed. In these latter cases, the carbonyl compound is treated with a diol, and triethyl orthoformate is used as a water scavenger. All these methods avoid the use of a Dean-Stark trap.

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A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst, Ram S. Mohan, Jason M. Bothwell, Veronica V. Angeles, James P. Carolan, Margaret E. Olson Dec 2009

A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst, Ram S. Mohan, Jason M. Bothwell, Veronica V. Angeles, James P. Carolan, Margaret E. Olson

Ram S. Mohan

The most common method for the deprotection ofTBDMS ethers utilizes stoichiometric amounts of tetrabutylammonium fluoride, n-Bu4N+F(TBAF), which is highly corrosive and toxic. We have developed a mild and chemoselective method for the deprotection ofTBDMS, TES, and TIPS ethers using iron(III) tosylate as a catalyst. Phenolic TBDMS ethers, TBDPS ethers and the BOC group are not affected under these conditions. Iron(III) tosylate is an inexpensive, commercially available, and non-corrosive reagent.

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Iron(Iii) Tosylate-Catalyzed Deprotection Of Aromatic Acetals In Water, Ram S. Mohan, Margaret E. Olson, James P. Carolan, Michael V. Chiodo, Phillip R. Lazzara Dec 2009

Iron(Iii) Tosylate-Catalyzed Deprotection Of Aromatic Acetals In Water, Ram S. Mohan, Margaret E. Olson, James P. Carolan, Michael V. Chiodo, Phillip R. Lazzara

Ram S. Mohan

The deprotection of aromatic as well as conjugated acetals and ketals in water is catalyzed by iron(III) tosylate (1.0–5.0 mol %). Iron(III) tosylate is an inexpensive and readily available catalyst. The use of water, the most environmentally benign solvent, makes this procedure especially attractive for acetal deprotection.

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In Your Element: Green Bismuth, Ram S. Mohan Dec 2009

In Your Element: Green Bismuth, Ram S. Mohan

Ram S. Mohan

No abstract provided.

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Bismuth(Iii) Bromide In Organic Synthesis. A Catalytic Method For The Allylation Of Tetrahydrofuranyl And Tetrahydropyranyl Ethers, Ram S. Mohan, Scott W. Krabbe, Veronica V. Angeles Dec 2009

Bismuth(Iii) Bromide In Organic Synthesis. A Catalytic Method For The Allylation Of Tetrahydrofuranyl And Tetrahydropyranyl Ethers, Ram S. Mohan, Scott W. Krabbe, Veronica V. Angeles

Ram S. Mohan

A bismuth bromide-catalyzed (10.0 mol %) multicomponent reaction involving the allylation of THF- and THP-ethers, followed by in situ derivatization with acetic anhydride to generate highly functionalized esters has been developed under solvent-free conditions. To the best of our knowledge, this is the first report of a catalytic procedure for the allylation of THF- and THP-ethers to yield ring-opened products.

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The Effect Of Catalyst Of The Reaction Of P-Hydroxybenzaldehyde With Acetic Anhydride: A Discovery-Oriented Green Laboratory Experiment, Ram Mohan, Matthew Huddle, Michael Devore Dec 2008

The Effect Of Catalyst Of The Reaction Of P-Hydroxybenzaldehyde With Acetic Anhydride: A Discovery-Oriented Green Laboratory Experiment, Ram Mohan, Matthew Huddle, Michael Devore

Ram S. Mohan

No abstract provided.

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Environmentally Friendly Organic Synthesis Using Bismuth Compounds. Bismuth(Iii) Bromide Catalyzed Synthesis Of Substituted Tetrahydroquinoline Derivatives, Ram S. Mohan, Jamie L. Rogers, Justin J. Ernat, Herbie Yung Dec 2008

Environmentally Friendly Organic Synthesis Using Bismuth Compounds. Bismuth(Iii) Bromide Catalyzed Synthesis Of Substituted Tetrahydroquinoline Derivatives, Ram S. Mohan, Jamie L. Rogers, Justin J. Ernat, Herbie Yung

Ram S. Mohan

The bismuth bromide catalyzed synthesis of a range of substituted tetrahydroquinoline derivatives via a three component coupling reaction between substituted anilines and enol ethers is reported. Bismuth compounds are attractive for use as catalysts because of their remarkably low toxicity. Bismuth bromide is relatively inexpensive and easy to handle, and hence preferable to other corrosive catalysts previously used for synthesis of tetrahydroquinoline derivatives.

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The Discovery-Oriented Approach To Organic Chemistry. 7. Rearrangement Of Trans-Stilbene Oxide With Bismuth Trifluoromethanesulfonate And Other Metal Triflates, Ram S. Mohan, James E. Christensen, Matthew G. Huddle, Jamie L. Rogers, Herbie Yung Aug 2008

The Discovery-Oriented Approach To Organic Chemistry. 7. Rearrangement Of Trans-Stilbene Oxide With Bismuth Trifluoromethanesulfonate And Other Metal Triflates, Ram S. Mohan, James E. Christensen, Matthew G. Huddle, Jamie L. Rogers, Herbie Yung

Ram S. Mohan

A microscale discovery-oriented experiment illustrating the rearrangement of trans-stilbene oxide using non-corrosive metal triflates as catalysts has been developed. The use of CDCl3 as the reaction solvent eliminates the need for any workup and avoids the use of highly toxic boron trifluoride etherate as a catalyst and additional reaction solvent.

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Platform Technology For Dienone And Phenol–Formaldehyde Architectures, Ram Mohan, Marilena Giarrusso, Luke Higham, Ulf Kreher, Anthony Rosamilia, Janet Scott, Christopher Strauss Dec 2007

Platform Technology For Dienone And Phenol–Formaldehyde Architectures, Ram Mohan, Marilena Giarrusso, Luke Higham, Ulf Kreher, Anthony Rosamilia, Janet Scott, Christopher Strauss

Ram S. Mohan

Claisen–Schmidt condensations, yielding only water as a by-product, performed on building blocks serving as shape-selective male or female terminals and unions, enable the preparation of diverse molecular structures including novel linear rods and semi-elliptical, rectangular or trapezoidal macrocycles. Isoaromatization affords a corresponding range of phenol-formaldehyde derivatives, in atom economical reactions.

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Environmentally Friendly Organic Synthesis Using Bismuth Compounds. Bismuth Trifluoromethanesulfonate-Catalyzed Allylation Of Dioxolanes, Ram Mohan, Matthew Spaffpord, James Christensen, Matthew Huddle, Joshua Lacey Dec 2007

Environmentally Friendly Organic Synthesis Using Bismuth Compounds. Bismuth Trifluoromethanesulfonate-Catalyzed Allylation Of Dioxolanes, Ram Mohan, Matthew Spaffpord, James Christensen, Matthew Huddle, Joshua Lacey

Ram S. Mohan

A bismuth trifluoromethanesulfonate (triflate)-catalyzed (2.0 mol-%) multicomponent reaction involving the allylation of dioxolanes followed by in situ derivatization with anhydrides to generate highly functionalized esters has been developed under solvent-free conditions. Most reagents used to date for allylation of dioxolanes are highly corrosive and are often required in stoichiometric amounts. In contrast, the use of a relatively non-toxic and non-corrosive bismuth(iii)-based catalyst makes this methodology especially attractive for scale-up.

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Environmentally Friendly Organic Synthesis Using Bismuth Compounds: Bismuth(Iii) Iodide Catalyzed Deprotection Of Acetals In Water, Ram S. Mohan, Aaron D. Bailey, Ashvin R. Baru, Kendall K. Tashe Dec 2007

Environmentally Friendly Organic Synthesis Using Bismuth Compounds: Bismuth(Iii) Iodide Catalyzed Deprotection Of Acetals In Water, Ram S. Mohan, Aaron D. Bailey, Ashvin R. Baru, Kendall K. Tashe

Ram S. Mohan

The chemoselective deprotection of a wide range of acetals and ketals in water is catalyzed by bismuth(III) iodide. Bismuth(III) compounds are remarkably nontoxic and hence are attractive as environmentally friendly catalysts.

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Synthesis Of Homoallyl Ethers Via Allylation Of Acetals And Aldehydes In Ionic Liquids, Ram Mohan, Peter Anzalone Dec 2006

Synthesis Of Homoallyl Ethers Via Allylation Of Acetals And Aldehydes In Ionic Liquids, Ram Mohan, Peter Anzalone

Ram S. Mohan

The TMS triflate catalyzed allylation of acetals to yield homoallyl ethers proceeds smoothly at room temperature in ionic liquids. A one-pot method for the conversion of aldehydes to homoallyl ethers in an ionic liquid has also been developed. This methodology is attractive because it allows allylations to be carried out at room temperature. Ionic liquids offer a convenient replacement for CH2Cl2, the commonly used solvent for such reactions.

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Iron(Iii) P-Toluenesulfonate Catalyzed Synthesis Of Homoallyl Ethers From Acetals And Aldehydes, Ram S. Mohan, Matthew J. Spafford, Erin D. Anderson, Joshua R. Lacey, Ann C. Palma Dec 2006

Iron(Iii) P-Toluenesulfonate Catalyzed Synthesis Of Homoallyl Ethers From Acetals And Aldehydes, Ram S. Mohan, Matthew J. Spafford, Erin D. Anderson, Joshua R. Lacey, Ann C. Palma

Ram S. Mohan

Iron(III) p-toluenesulfonate, Fe(OTs)3.6H20, is an inexpensive, versatile and commercially available catalyst for the allylation of acetals using allyltrimethylsilane to yield homoallyl ethers in moderate to good yields. The one-pot conversion of aldehydes to homoallyl ethers using alkoxysilanes has also been accomplished using Fe(OTs)3.6H20 as a catalyst. The use of mild reaction conditions and a relatively non-corrosive catalyst make this method an attractive option for the synthesis of a range of homoallyl ethers.

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Reactivity Of Ionic Liquids, Ram S. Mohan, Shahana Chowdhury, Janet L. Scott Dec 2006

Reactivity Of Ionic Liquids, Ram S. Mohan, Shahana Chowdhury, Janet L. Scott

Ram S. Mohan

Ionic liquids are becoming widely used in synthetic organic chemistry and yet relatively little attention has been paid to the intrinsic reactivity of these low temperature molten salts. Clues to the non-innocent nature of many ionic liquids are contained in the reports of altered reactivity of dissolved substrates, unexpected catalytic activity and unforeseen by-product formation. In this review, we focus on the reactivity of ionic liquids, as opposed to reactivity in ionic liquids (although discussion of the latter is often included where it aids understanding of the former).

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