About

Christopher C. Cummins is the Henry Dreyfus Professor of Chemistry at MIT. His research group focuses on developing new methods of inorganic synthesis to address a variety of interesting questions. His work encompasses chemical synthesis, reaction discovery, reagent development, and mechanistic studies. Under his direction, the group is engaged in developing anthracene-based precursors to reactive intermediates, including P2, aminophosphinidenes, SO, phosphinidene chalcogenides, and other heavier main-group multiply bonded species not stabilized by sterically demanding substituents. The research also involves advancing group transfer reactivity, elaborating ligands from P2 cycloaddition chemistry for catalysis applications, and creating building blocks for poly and oligophosphate containing compounds, with applications in tri and tetraphosphorylation of nucleophiles. Additionally, his group investigates transition-metal mediated processes for phosphinidene transfer to olefins, aiming to develop methods such as phosphiranation, the phosphorus counterpart to epoxidation or aziridination. His research integrates synthetic chemistry with quantum chemical investigations to understand potential energy surfaces and chemical bonding nuances in novel systems. A significant aspect of his work is phosphorus sustainability, focusing on energy-efficient and waste-minimal routes to value-added phosphorus chemicals from recovered and recycled materials.

Research topics

• Organic chemistry
• Chemistry
• Crystallography
• Materials science
• Biochemistry
• Stereochemistry
• Environmental science
• Mathematics
• Biochemical engineering
• Engineering
• Nanotechnology
• Process engineering

Selected publications

• Reactions of diazoboranes with oxygen enables the synthesis and isolation of dioxaboriranes

  Nature Chemistry · 2026-04-24 · 1 citations

  articleOpen accessSenior author

  Cyclic peroxides are highly reactive oxygen-containing species that play important roles in chemical synthesis, yet, aside from dioxiranes (R2CO2), well-defined cyclic peroxides of main-group elements remain rare. In particular, cyclic peroxides featuring boron–oxygen frameworks have not been explored. Here we show that boron peroxides can be prepared directly from accessible boron precursors and molecular oxygen under mild conditions. Specifically, reactions of diazoboranes with triplet oxygen afford a family of cyclic dioxaboriranes, including both neutral and anionic variants. These compounds exhibit distinct reactivity: neutral species behave as electrophilic oxygen-atom donors, whereas the anionic analogue is nucleophilic and reacts with carbon dioxide. Computational studies explain why these boron peroxides form thermally, in contrast to dioxiranes that require strict photochemical control. Finally, we show that cyclic dioxaboriranes can be converted into acyclic boron peroxide derivatives, highlighting opportunities for controlling peroxide structure and reactivity at boron. Cyclic peroxides are highly reactive oxygen-containing species that play important roles in chemical synthesis. Now, the reaction between diazoboranes and triplet oxygen affords a family of cyclic dioxaboriranes, including both neutral and anionic variants. Neutral species behave as electrophilic oxygen-atom donors, whereas anionic analogues are nucleophilic and react with carbon dioxide.

  PublisherOA PDFDOI

• Ortho-phosphite (PO33−): Mechanochemical Synthesis of a Missing Oxoanion and Precursor to Value-Added Organophosphorus Compounds

  ACS Central Science · 2025-11-26 · 2 citations

  articleOpen accessSenior authorCorresponding

  Despite the ubiquity of the well-known phosphorus polyanion phosphite (HPO32−), it appears to be the case that no simple salt of the corresponding conjugate base (PO33−, “ortho-phosphite”) has ever been reported. We report the synthesis and characterization of this elusive species as a major component of a mixture obtained upon mechanochemical reduction of condensed phosphates, as evidenced by solid-state 31P NMR and Raman spectroscopy as well as subsequent reactivity studies. To corroborate the 31P NMR spectroscopic assignment, we independently generated Na3PO3 and K3PO3 by deprotonation of Na2HPO3 with NaCH2SiMe3 and of K2HPO3 with KCH2Ph, respectively, providing an orthogonal route to PO33− salts whose spectroscopic signatures match those observed in the mixture obtained by mechanochemical reduction. We further found that ortho-phosphite can act as a precursor for various phosphorus chemicals, such as P(OSiMe3)3 (46%), which is already well established as a precursor to a plethora of useful organophosphorus compounds. Therefore, our results not only establish the first formal pathway from P(V) phosphate starting materials to P(OSiMe3)3 without the intermediacy of white phosphorus, but also open the door to a broad range of downstream transformations based on this sustainable pathway. Additionally, BaHPO3·H2O (66%), OP(OMe)2Me (DMMP), and OP(OBn)2Bn (DBBP) have been generated directly from ortho-phosphite, all traditionally synthesized from white phosphorus.

  PublisherDOI

• Unlocking the Ambiphilicity of the Boryl Anion: Synthesis and Reactivity of an Anionic Diazoborane

  Journal of the American Chemical Society · 2025-06-10 · 15 citations

  articleCorresponding

  Reported boryl anions (R2B–) often exhibit n–p conjugation between the boron atom and adjacent heteroatoms, with their nucleophilicity being the primary focus. In this work, we present evidence that aryl-substituted boryl anions (Ar2B–) can exhibit ambiphilicity. Specifically, the diazoborane anion [K(2.2.2-cryptand)]+Dmp(Mes)BN2– (3, Dmp = 2,6-dimesitylphenyl, Mes = 2,4,6-trimethylphenyl) has been synthesized via diazo transfer using Carpino’s hydrazine as a reagent. Compound 3 exhibits a strong tendency to release dinitrogen, acting as a free boryl anion Dmp(Mes)B– source. Ligand exchange reactions with carbon monoxide and 2,6-xylyl isocyanide highlight the metallomimetic (ambiphilic) behavior of 3. The ambiphilic nature of 3 further enables its reaction with nitrous oxide to yield an oxoborane anion (R2BO–). Compound 3 also reacts with carbon dioxide to form the cycloaddition product R2B(N2CO2)− (7). Additionally, the boryl-N2 anion undergoes N2 release upon heating with LiCl or irradiation, yielding different bond activation products. The underlying mechanisms of these reactions were investigated through in-depth DFT analysis.

  PublisherDOI

• Back Cover: Monodisperse Chemical Oligophosphorylation of Peptides via Protected Oligophosphorimidazolide Reagents (Angew. Chem. Int. Ed. 11/2025)

  Angewandte Chemie International Edition · 2025-02-14

  paratextOpen accessCorresponding

  Oligophosphorylated peptides were prepared by Kevin Qian, Björn Hanf, Christopher Cummins, and Dorothea Fiedler in their Research Article (e202419147). Oligophosphorimidazolide reagents are presented that enable the conjugation of multiple phosphates to phosphopeptides, yielding derivatives with monodisperse phosphate chain lengths. The picture illustrates different peptides with varying phosphate chain lengths, bearing either a terminal protecting group or a free oligophosphate moiety.

  PublisherOA PDFDOI

• A Remarkable Catalyst-Free Photochemical Alkene Hydrophosphination with Bis(trimethylsilyl)phosphonite

  JACS Au · 2025-06-03 · 2 citations

  articleOpen accessCorresponding

  This publication delves into a comprehensive exploration of a new synthetic route to functionalized phosphorus-derived compounds. Bis(trimethylsilyl)phosphonite HP(OSiMe3)2, prepared in a high yield from H3PO2, was found to be an excellent reagent for hydrophosphination of activated, unactivated, and amino acid-derived olefins under UV irradiation and catalyst-, solvent- and glovebox-free conditions. The resulting phosphorus trivalent compounds have been subjected to postfunctionalization, leading to the formation of H-phosphinate, phosphonate, and thiophosphonate end products in good to excellent yields. With a combination of experimental and theoretical calculations, the mechanism for this hydrophosphination reaction has been investigated, revealing a radical process.

  PublisherDOI

• Hexamethylbenzene elimination enables the generation of transient, sterically unhindered multiply bonded boron species

  Chemical Science · 2025-01-01 · 4 citations

  articleOpen accessSenior author

  ring, respectively, implying the involvement of transient oxoborane (PhB[triple bond, length as m-dash]O) and iminoborane intermediates (PhB[triple bond, length as m-dash]NPh), respectively. Furthermore, boranorbornadiene also undergoes 2,3-insertion with mesityl isocyanate (MesNCO), affording a fused 6/5-membered heterocycle 11. This insertion profile is analogous to the insertion of phenyl azide into 1.

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• Coordination Chemistry of Small Molecule Activation, Generation, and Transfer

  Bulletin of Japan Society of Coordination Chemistry · 2025-06-17

  articleOpen access1st authorCorresponding

  Researchers in the authorʼs laboratory have investigated small-molecule activation reactions using low-coordinate early transition-metal complexes supported by sterically demanding N-hydrocarbyl anilide ligands. Such complexes are potent one, two, or three-electron reducing agents, and early on the focus was on small molecules including N2, NO, and N2O with metalligand multiply bonded systems formed as products of the bond activation reactions. Reactions with P4 (white phosphorus) and As4 led respectively to complexes with metal-phosphorus or metal-arsenic triple bonds. This led to the notion of element or molecule activation using transition metals, to be followed by atom or group transfer to organic molecules. Phosphorus transfer was achieved in a novel phosphaalkyne synthesis method involving transfer of a P4-derived phosphorus atom using a niobium complex. Next, diphosphorus transfer was achieved using first a niobium and then an anthracene-based platform, the latter culminating in a synthesis of diphosphatriazolate, P2N3 −. Triphosphorus group transfer was harnessed in a synthesis of AsP3. This was echoed by the synthesis of HCP3. Anthracene emerged as a privileged two-electron platform for the construction of molecular precursors to reactive intermediates including HCP, P2, and phosphorus mononitride, PN. This account thus describes an arc from the activation of kinetically inert small molecules to the synthesis, transfer, or transient generation of reactive ones.

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• Intramolecular Oxidative Addition Triggered by One-Electron Oxidation of Molybdenum(<scp>iii</scp>) Tris(anilide): Generation of Molybdenum(v) Imido Aryl Bis(anilide) by Autocatalysis

  Organometallics · 2025-01-21 · 1 citations

  articleOpen accessCorresponding

  One-electron oxidation of molybdenum(iii) tris(anilide) Mo(N[tBu]Ar)3 (Ar: ArMe = 3,5-Me2C6H3 and ArPh = 3,5-Ph2C6H3) led to intramolecular oxidative addition across the N–Cipso bond of a ligated anilide to form the cationic Mo(vi) imido/aryl bis(anilide) complexes [Mo(N[tBu]Ar)2(═NtBu)(Ar)][B(C6F5)4]. One-electron reduction of [Mo(N[tBu]ArMe)2(═NtBu)(ArMe)][B(C6F5)4] allowed access to the neutral Mo(v) species [Mo(N[tBu]ArMe)2(═NtBu)(ArMe)]. The d1 electron configuration was confirmed through EPR spectroscopy and the Evans method. Compound [Mo(N[tBu]ArMe)2(═NtBu)(ArMe)] was experimentally and theoretically shown to be stable against reductive elimination which would form the energetically less favorable Mo(N[tBu]Ar)3. The high activation barrier has so far prevented Mo(N[tBu]Ar)3 from isomerizing spontaneously to [Mo(N[tBu]ArMe)2(═NtBu)(ArMe)]. An autocatalytic process was developed to access [Mo(N[tBu]ArMe)2(═NtBu)(ArMe)] through reduction of [Mo(N[tBu]ArMe)2(═NtBu)(ArMe)][B(C6F5)4] by Mo(N[tBu]Ar)3, which itself was converted into the oxidizing agent. Attempts to access stable Mo(iv) cations with 4,4′-bipyridine only resulted in labile binding of 4,4′-bipyridine to one or two molybdenum(iii) tris(anilide) complexes.

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• Synthetic Applications of Carpino’s Hydrazine

  Accounts of Chemical Research · 2025-11-04

  articleSenior authorCorresponding

  ConspectusReactive intermediates are valuable and intriguing in synthetic chemistry, but their high reactivity often makes them challenging to handle. Therefore, developing strategies to generate these species in a mild and controlled manner is crucial. One effective approach involves embedding the reactive intermediate within a molecular scaffold. Upon gentle heating, the scaffold undergoes fragmentation, liberating the desired intermediate. Ideally, the resulting byproducts are inert and do not participate in the subsequent reaction. Carpino’s hydrazine, H2N2A (A = C14H10 or anthracene), thus serves as an excellent scaffold candidate. By attaching a functional group of interest (E) to the hydrazine, the resulting compound EN2A is expected to undergo fragmentation, releasing E, dinitrogen (N2), and anthracene.In this account, we describe our efforts to develop a series of molecular precursors featuring the composition EN2A (E = C, CH2, SO, RLB, and R2B). These precursors are expected to be capable of releasing a single carbon atom, methylene, sulfur monoxide, borylene, and boryl anion, respectively. Interestingly, the fragmentation behavior of these hydrazine-based precursors is highly dependent on the substituents at nitrogen. For CN2A, H2CN2A, and OSN2A, the precursors are stable at room temperature. Meanwhile, for (RLB)N2A, and (R2B)N2A, the precursors are transient intermediate and undergo anthracene extrusion even at low temperatures.While the initial goal was to generate reactive species E, many cases have shown that free intermediates are not necessarily required for group transfer reactions. Instead, the hydrazine precursors often facilitate group transfer through highly selective, associative mechanisms (Type A). Additionally, the diazo intermediates formed via primary fragmentation are of particular interest, as they display reactivity analogous to diazoalkanes (R2CN2) or organic azides (RN3, Type B). Notably, although hydrazine precursors, diazo intermediates, and low-valent species all participate in group transfer reactions, they exhibit distinct electronic structures. Consequently, their reactivity patterns and selectivity vary significantly, underscoring the diverse chemical space accessible through this versatile platform.We believe that continued development of Carpino’s hydrazine derivatives holds significant potential for uncovering new reactive intermediates and gaining deeper mechanistic insights. Moreover, the reactivity demonstrated with boron may be extended to other main group elements, potentially enabling access to a broader class of compounds featuring terminal N2 complexes.

  PublisherDOI

• Rücktitelbild: Monodisperse Chemical Oligophosphorylation of Peptides via Protected Oligophosphorimidazolide Reagents (Angew. Chem. 11/2025)

  Angewandte Chemie · 2025-02-14

  articleOpen accessCorresponding

  Oligophosphorylated peptides were prepared by Kevin Qian, Björn Hanf, Christopher Cummins, and Dorothea Fiedler in their Research Article (e202419147). Oligophosphorimidazolide reagents are presented that enable the conjugation of multiple phosphates to phosphopeptides, yielding derivatives with monodisperse phosphate chain lengths. The picture illustrates different peptides with varying phosphate chain lengths, bearing either a terminal protecting group or a free oligophosphate moiety.

  PublisherOA PDFDOI

Recent grants

• Synthesis of d- and p-Block Element Molecules, Reagents, and Precursors

  NSF · $450k · 2017–2020

• Synthesis of d- and p-Block Element Molecules, Reagents, and Precursors

  NSF · $624k · 2014–2017

• Reagents for Chemical Oligophosphorylation, Synthesis of Oligophosphate-Organic Molecule Conjugates, and Biochemical Studies

  NIH · $1.2M · 2020–2026

• Synthesis Using Group 15 Elements

  NSF · $600k · 2011–2015

• Synthesis of d- and p-Block Element Molecules, Reagents, and Precursors

  NSF · $495k · 2020–2023

Frequent coauthors

• Carl D. Hoff

  University of Miami

  118 shared

• E.V. Rybak-Akimova

  Tufts University

  114 shared

• Jun Okuda

  RWTH Aachen University

  113 shared

• Laurent Maron

  Laboratoire de Physique et Chimie des Nano-Objets

  106 shared

• Joshua S. Figueroa

  University of California, San Diego

  79 shared

• A. Mendiratta

  Lam Research (United States)

  77 shared

• Daniel G. Nocera

  77 shared

• Wesley J. Transue

  Stanford University

  72 shared

Labs

• Cummins groupPI