1
|
Adjei JA, Kerr MA, Ragogna PJ. UV induced hydrophosphination of dimethyl 2-vinylcyclopropane-1,1-dicarboxylate towards phosphine chalcogenides. Dalton Trans 2023; 52:6739-6748. [PMID: 37129227 DOI: 10.1039/d3dt00791j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Dimethyl 2-vinylcyclopropane-1,1-dicarboxylate underwent a hydrophosphination reaction with either a primary or secondary phosphine under photolytic conditions. Notably, a free radical initiator was not required. The resulting tertiary phosphines were derivatized using S8 to afford moisture and air stable yellow or colorless oils in a 27%-73% isolated yield. A series of control reactions were performed, and we propose that this UV induced hydrophosphination reaction proceeds through a radical mechanism.
Collapse
Affiliation(s)
- Jeanette A Adjei
- The University of Western Ontario, Department of Chemistry, UWO Chemistry Building, 1151 Richmond Street, London, ON N6A, Canada.
| | - Michael A Kerr
- The University of Western Ontario, Department of Chemistry, UWO Chemistry Building, 1151 Richmond Street, London, ON N6A, Canada.
| | - Paul J Ragogna
- The University of Western Ontario, Department of Chemistry, UWO Chemistry Building, 1151 Richmond Street, London, ON N6A, Canada.
| |
Collapse
|
2
|
Moussa ME, Kahoun T, Marquardt C, Ackermann MT, Hegen O, Seidl M, Timoshkin AY, Virovets AV, Bodensteiner M, Scheer M. Three- and Five-Membered Anionic Chains of Pnictogenylboranes. Chemistry 2023; 29:e202203206. [PMID: 36478481 DOI: 10.1002/chem.202203206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 12/06/2022] [Accepted: 12/07/2022] [Indexed: 12/12/2022]
Abstract
An unprecedented family of three- and five-membered substituted anionic derivatives of parent pnictogenylboranes is herein reported. Reacting various combinations of the pnictogenylboranes H2 E'-BH2 -NMe3 (E'=P, As) with pnictogen-based nucleophiles MER1R2 (E=P, As; R1=H, R2=t Bu; R1=R2=Ph; M=Na, K) allows for the isolation of the unsymmetrical products [Na(18-crown-6)][H2 E'-BH2 -EHt Bu] (3: E=E'=P; 4: E=E'=As; 5: E=As, E'=P) and [M(C)][H2 E'-BH2 -EPh2 ] (7: E=E'=P, M=Na, C=18-crown-6; 8: E=E'=As; M=K, C=[2.2.2]cryptand; 9: E=P, E'=As, M=Na, C=[2.2.2]cryptand; 10: E=As, E'=P, M=K, C=[2.2.2]cryptand). [Na(18-crown-6)][H2 As-BH2 -t BuPH-BH3 ] (6) is only accessible by a different pathway, using t BuPH2 , BH3 ⋅ SMe2 and NaNH2 as starting materials. Additionally, the synthesis of symmetrical diphenyl-substituted compounds [M(18-crown-6)][Ph2 E-BH2 -EPh2 ] (11: E=P, M=Na; 12: E=As, M=K) is reported which can be regarded as isostructural inorganic, negatively charged analogs of dppm (1,1-bis(diphenylphosphino)methane) and dpam (1,1-bis(diphenylarsino)methane). Furthermore, an elongation of the pnictogen boron backbone in compounds 3, 7 and 9' (similar compound to 9, stabilized however by 18-crown-6), is attainable by reacting them with the pnictogenylboranes H2 E'-BH2 -NMe3 leading to corresponding five-membered chain-like compounds [Na(18-crown-6)][H2 E-BH2 -R1R2P-BH2 -E'H2 ] (E=E'=P, R1=H, R2=t Bu (13); E=E'=P, R1=R2=Ph (14); E=E'=As, R1=R2=Ph (15); E=P, E'=As, R1=R2=Ph (16)). Finally, the thermodynamics of the reaction pathways were evaluated by quantum chemical computations.
Collapse
Affiliation(s)
- Mehdi Elsayed Moussa
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Tobias Kahoun
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Christian Marquardt
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Matthias T Ackermann
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Oliver Hegen
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Michael Seidl
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, Universitetskaya nab. 7/9, 199034, St. Petersburg, Russia
| | - Alexander V Virovets
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Michael Bodensteiner
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| | - Manfred Scheer
- Institut für Anorganische Chemie der, Universität Regensburg, 93040, Regensburg, Germany
| |
Collapse
|
3
|
Race JJ, Heyam A, Wiebe MA, Diego-Garcia Hernandez J, Ellis CE, Lei S, Manners I, Weller AS. Polyphosphinoborane Block Copolymer Synthesis Using Catalytic Reversible Chain-Transfer Dehydropolymerization. Angew Chem Int Ed Engl 2023; 62:e202216106. [PMID: 36394131 PMCID: PMC10107156 DOI: 10.1002/anie.202216106] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 11/15/2022] [Accepted: 11/17/2022] [Indexed: 11/19/2022]
Abstract
An amphiphilic block copolymer of polyphosphinoborane has been prepared by a mechanism-led strategy of the sequential catalytic dehydropolymerization of precursor monomers, H3 B ⋅ PRH2 (R=Ph, n-hexyl), using the simple pre-catalyst [Rh(Ph2 PCH2 CH2 PPh2 )2 ]Cl. Speciation, mechanism and polymer chain growth studies support a step-growth process where reversible chain transfer occurs, i.e. H3 B ⋅ PRH2 /oligomer/polymer can all coordinate with, and be activated by, the catalyst. Block copolymer [H2 BPPhH]110 -b-[H2 BP(n-hexyl)H]11 can be synthesized and self-assembles in solution to form either rod-like micelles or vesicles depending on solvent polarity.
Collapse
Affiliation(s)
- James J Race
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK.,Chemistry Research Laboratories, University of Oxford, Oxford, OX1 3TA, UK
| | - Alex Heyam
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| | - Matthew A Wiebe
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | | | - Charlotte E Ellis
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Shixing Lei
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Ian Manners
- Department of Chemistry, University of Victoria, Victoria, BC, V8P 5C2, Canada.,Centre for Advanced Materials and Related Technology (CAMTEC), University of Victoria, Victoria, BC, V8P 5C2, Canada
| | - Andrew S Weller
- Department of Chemistry, University of York, Heslington, York, YO10 5DD, UK
| |
Collapse
|
4
|
Wiebe MA, Kundu S, LaPierre EA, Patrick BO, Manners I. Transition-Metal-Free Dehydropolymerization of Phosphine-Boranes at Ambient Temperature. Chemistry 2023; 29:e202202897. [PMID: 36196020 DOI: 10.1002/chem.202202897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Indexed: 11/16/2022]
Abstract
Stoichiometric reaction of phosphine-borane adducts RR'PH⋅BH3 (R=Ph, R'=H, Ph, Et, and R=R'=t Bu) with the strong acid HNTf2 (Tf=SO2 CF3 ) leads to H2 elimination and the formation of the triflimido derivatives, RR'PH⋅BH2 (NTf2 ). Subsequent deprotonation by using bases, such as diisopropylethylamine or the carbene IPr (IPr=N,N'-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), led to the formation of P-mono- or -disubstituted polyphosphinoboranes [RR'P-BH2 ]n . Evidence for the intermediacy of transient phosphinoborane monomers, RR'PBH2 , was provided by trapping reactions.
Collapse
Affiliation(s)
- Matthew A Wiebe
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada
| | - Subrata Kundu
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada.,Department of Chemistry, Indian Institute of Technology Delhi Hauz Khas, New Delhi, 110016, India
| | - Etienne A LaPierre
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada
| | - Brian O Patrick
- Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, British Columbia, V6T 1Z1, Canada
| | - Ian Manners
- Department of Chemistry, University of Victoria, 3800 Finnerty Rd, Victoria, British Columbia, V8P 5 C2, Canada
| |
Collapse
|
5
|
Dannenberg SG, Seth DM, Finfer EJ, Waterman R. Divergent Mechanistic Pathways for Copper(I) Hydrophosphination Catalysis: Understanding That Allows for Diastereoselective Hydrophosphination of a Tri-substituted Styrene. ACS Catal 2022. [DOI: 10.1021/acscatal.2c05221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Steven G. Dannenberg
- Department of Chemistry, University of Vermont, Burlington, Vermont 05405-0125, United States
| | - Dennis M. Seth
- Department of Chemistry, University of Vermont, Burlington, Vermont 05405-0125, United States
| | - Emma J. Finfer
- Department of Chemistry, University of Vermont, Burlington, Vermont 05405-0125, United States
| | - Rory Waterman
- Department of Chemistry, University of Vermont, Burlington, Vermont 05405-0125, United States
| |
Collapse
|
6
|
Geeson MB, Tanaka K, Taakili R, Benhida R, Cummins CC. Photochemical Alkene Hydrophosphination with Bis(trichlorosilyl)phosphine. J Am Chem Soc 2022; 144:14452-14457. [PMID: 35926231 DOI: 10.1021/jacs.2c05248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Bis(trichlorosilyl)phosphine (HP(SiCl3)2, 1) was prepared from [TBA][P(SiCl3)2] ([TBA]2, TBA = tetra-n-butylammonium) and triflic acid in 36% yield. Phosphine 1 is an efficient reagent for hydrophosphination of unactivated terminal olefins under UV irradiation (15-60 min) and gives rise to bis(trichlorosilyl)alkylphosphines (RP(SiCl3)2, R = (CH2)5CH3, 88%; (CH2)7CH3, 98%; (CH2)2C(CH3)3, 76%; CH2Cy, 93%; (CH2)2Cy, 95%; CH2CH(CH3)(CH2)2CH3, 82%; (CH2)3O(CH2)3CH3, 95%; (CH2)3Cl, 83%; (CH2)2SiMe3, 92%; (CH2)5C(H)CH2, 44%) in excellent yields. The products require no further purification beyond filtration and removal of volatile material under reduced pressure. The P-Si bonds of prototypical products RP(SiCl3)2 (R = -(CH2)5CH3, -(CH2)7CH3) are readily functionalized to give further phosphorus-containing products: H3C(CH2)7PCl2 (56%), [H3C(CH2)5P(CH2Ph)3]Br (84%), H3C(CH2)7PH2 (61%), H3C(CH2)5P(O)(H)(OH) (81%), and H3C(CH2)5P(O)(OH)2 (55%). Experimental mechanistic investigations, accompanied by quantum chemical calculations, point toward a radical-chain mechanism. Phosphine 1 enables the fast, high-yielding, and atom-efficient preparation of compounds that contain phosphorus-carbon bonds in procedures that bypass white phosphorus (P4), a toxic and high-energy intermediate of the phosphorus industry.
Collapse
Affiliation(s)
- Michael B Geeson
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Keita Tanaka
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Rachid Taakili
- Department of Chemical and Biochemical Sciences - Green Process Engineering, Mohammed VI Polytechnic University, Ben Guerir 43150, Morocco.,Institut de Chimie de Nice, UMR7272, Université Côte d'Azur, Nice 06103, France
| | - Rachid Benhida
- Department of Chemical and Biochemical Sciences - Green Process Engineering, Mohammed VI Polytechnic University, Ben Guerir 43150, Morocco.,Institut de Chimie de Nice, UMR7272, Université Côte d'Azur, Nice 06103, France
| | - Christopher C Cummins
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| |
Collapse
|
7
|
Belli RG, Yang J, Bahena EN, McDonald R, Rosenberg L. Mechanism and Catalyst Design in Ru-Catalyzed Alkene Hydrophosphination. ACS Catal 2022. [DOI: 10.1021/acscatal.1c05636] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Roman G. Belli
- Department of Chemistry, University of Victoria, P.O. Box 1700, STN CSC, Victoria, British Columbia V8W 2Y2, Canada
| | - Jin Yang
- Department of Chemistry, University of Victoria, P.O. Box 1700, STN CSC, Victoria, British Columbia V8W 2Y2, Canada
| | - Erick Nuñez Bahena
- Department of Chemistry, University of Victoria, P.O. Box 1700, STN CSC, Victoria, British Columbia V8W 2Y2, Canada
| | - Robert McDonald
- X-ray Crystallography Laboratory, Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Lisa Rosenberg
- Department of Chemistry, University of Victoria, P.O. Box 1700, STN CSC, Victoria, British Columbia V8W 2Y2, Canada
| |
Collapse
|
8
|
Knights AW, Nascimento MA, Manners I. An investigation of polyphosphinoboranes as flame-retardant materials. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
9
|
Song Q, Shang K, Xue T, Wang Z, Pei D, Zhao S, Nie J, Chang Y. Macrocyclic Photoinitiator Based on Prism[5]arene Matching LEDs Light with Low Migration. Macromol Rapid Commun 2021; 42:e2100299. [PMID: 34173296 DOI: 10.1002/marc.202100299] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/02/2021] [Indexed: 12/30/2022]
Abstract
In this work, a naphthalene-based macrocycle prism[5]arene (NP5 OCH3 ) is developed as a novel kind of photoinitiator. When NP5 OCH3 is irradiated under light, the bond between methylene and naphthalene can be quickly broken owning to the existence of ring tension. The macrocycle is cleaved to linear oligomer biradicals, which can effectively initiate the free radical photopolymerization of acrylate monomers. Compared with conventional photoinitiators, NP5 OCH3 has strong light absorption in the wavelength range of 365-405 nm, so it can well match the environment-friendly light-emitting diodes (LEDs) light source to realize highly efficient initiation. In addition, there is no small molecule fragment generated during NP5 OCH3 fracture, and the resulted linear oligomer biradicals can be immobilized in the polymer after initiating polymerization, so NP5 OCH3 photoinitiators show much lower migration rate and cytotoxicity. Cleavable macrocycle prismarene may provide a new idea for the design of safe and efficient photoinitiators matching long wavelength light.
Collapse
Affiliation(s)
- Qiuyan Song
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Kun Shang
- College of Medicine, Yan'an University, Yan'an, Shaanxi Province, 716000, P. R. China
| | - Tanlong Xue
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Zongcheng Wang
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Di Pei
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Shuai Zhao
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Jun Nie
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| | - Yincheng Chang
- State Key Laboratory of Chemical Resource Engineering, Beijing Laboratory of Biomedical Materials, Changzhou Institute of Advanced Materials, Beijing University of Chemical Technology, Beijing, 100029, P. R. China
| |
Collapse
|
10
|
Panova Y, Khristolyubova A, Zolotareva N, Sushev V, Galperin V, Rumyantcev R, Fukin G, Kornev A. Interaction of dicoordinate phosphorus with boranes: chemistry of 3a,6a-diaza-1,4-diphosphapentalene as masked phosphinidene. Dalton Trans 2021; 50:5890-5898. [PMID: 33949550 DOI: 10.1039/d1dt00747e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Treatment of 3a,6a-diaza-1,4-diphosphapentalene (DDP) with an excess of PhBCl2 yields the corresponding bis(borane) adduct DDP(PhBCl2)2 (14), demonstrating the availability of two lone pairs on the phosphorus center. The reaction between DDP and B(C6F5)3 yields (1 : 1) phosphino-borane complex 16. The free lone electron pair on the pyramidal P atom in 16 participates in the intramolecular non-covalent interactions P(1)F(1) and P(1)F(6) giving additional 3.9 and 2.8 kcal mol-1, respectively, for stabilization of the complex. This through-space interaction appears in the 31P NMR spectrum as large spin-spin coupling constants of 271 and 219 Hz. The addition of water to 16 (1 : 1) leads to the formation of the insertion product 17 having -H2P-O-B(C6F5)3 moiety. The reaction of DDP with BH3·SMe2 proceeds in several stages, which include the insertion of the masked phosphinidene into the B-H and P-H bonds of the intermediate compounds followed by the dehydrocoupling step and formation of diphosphine 18. The last compound exists in solution as a set of stereoisomers.
Collapse
Affiliation(s)
- Yulia Panova
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| | - Alexandra Khristolyubova
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| | - Natalia Zolotareva
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| | - Vyacheslav Sushev
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| | - Vadim Galperin
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| | - Roman Rumyantcev
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| | - Georgy Fukin
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| | - Alexander Kornev
- G. A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Science 49 Tropinin str., 603137 Nizhny Novgorod, Russia.
| |
Collapse
|
11
|
Pomogaeva AV, Timoshkin AY. Stability and Electronic Structure of Donor-Acceptor Stabilized Group 13/15 Oligomers. J Phys Chem A 2021; 125:3415-3424. [PMID: 33861081 DOI: 10.1021/acs.jpca.1c02258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Electronic structures and thermodynamic characteristics of chain inorganic group 13-15 oligomers [H2MEH2]n (M = B, Al, Ga, E = P, As; n = 4-15) are presented. Donor-acceptor interaction with both Lewis acids and Lewis bases effectively stabilizes chain isomers with respect to spontaneous cyclization and significantly changes their electronic structure.
Collapse
Affiliation(s)
- Anna V Pomogaeva
- Institute of Chemistry, St. Petersburg State University, Universitetskaya emb. 7/9, St. Petersburg, 199034, Russia
| | - Alexey Y Timoshkin
- Institute of Chemistry, St. Petersburg State University, Universitetskaya emb. 7/9, St. Petersburg, 199034, Russia
| |
Collapse
|
12
|
Resendiz-Lara DA, Annibale VT, Knights AW, Chitnis SS, Manners I. High Molar Mass Poly(alkylphosphinoboranes) via Iron-Catalyzed Dehydropolymerization. Macromolecules 2020. [DOI: 10.1021/acs.macromol.0c02082] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Vincent T. Annibale
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| | - Alastair W. Knights
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Saurabh S. Chitnis
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
| | - Ian Manners
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, U.K
- Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, British Columbia V8P 5C2, Canada
| |
Collapse
|
13
|
MacMillan JWM, Marczenko KM, Johnson ER, Chitnis SS. Hydrostibination of Alkynes: A Radical Mechanism*. Chemistry 2020; 26:17134-17142. [PMID: 32706129 DOI: 10.1002/chem.202003153] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Indexed: 11/09/2022]
Abstract
The addition of Sb-H bonds to alkynes was reported recently as a new hydroelementation reaction that exclusively yields anti-Markovnikov Z-olefins from terminal acetylenes. We examine four possible mechanisms that are consistent with the observed stereochemical and regiochemical outcomes. A comprehensive analysis of solvent, substituent, isotope, additive, and temperature effects on hydrostibination reaction rates definitively refutes three ionic mechanisms involving closed-shell charged intermediates. Instead the data support a fourth pathway featuring open-shell neutral intermediates. Density-functional theory (DFT) calculations are consistent with this model, predicting an activation barrier that is in agreement with the experimental value (Eyring analysis) and a rate limiting step that is congruent with the experimental kinetic isotope effect. We therefore conclude that hydrostibination of arylacetylenes is initiated by the generation of stibinyl radicals, which then participate in a cycle featuring SbII and SbIII intermediates to yield the observed Z-olefins as products. This mechanistic understanding will enable rational evolution of hydrostibination as a synthetic methodology.
Collapse
Affiliation(s)
- Joshua W M MacMillan
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, B3H 4R2, Halifax, Canada
| | - Katherine M Marczenko
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, B3H 4R2, Halifax, Canada
| | - Erin R Johnson
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, B3H 4R2, Halifax, Canada
| | - Saurabh S Chitnis
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, B3H 4R2, Halifax, Canada
| |
Collapse
|
14
|
Arz MI, Knights AW, Manners I. Synthesis and Post-Polymerization Functionalization of Halogen-Substituted Polyphosphinoboranes to Access Alkyne-Functionalized Derivatives. Macromol Rapid Commun 2019; 41:e1900468. [PMID: 31880037 DOI: 10.1002/marc.201900468] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 10/19/2019] [Indexed: 01/12/2023]
Abstract
Catalytic dehydropolymerization of halogen-functionalized phosphine-boranes (4-X-C6 H4 )PH2 ⋅BH3 (1a: X = Br, 1b: X = I) with [CpFe(CO)2 (OTf)] at 100 °C provides convenient access to halogen-functionalized polyphosphinoboranes [(4-X-C6 H4 )PH-BH2 ]n (2a: X = Br, 2b: X = I). These polymers are useful precursors for post-polymerization functionalization, which is demonstrated by Sonogashira coupling under mild conditions to yield the alkynyl-functionalized polyphosphinoborane [(4-PhCC-C6 H4 )PH-BH2 ]n (3).
Collapse
Affiliation(s)
- Marius I Arz
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Alastair W Knights
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK
| | - Ian Manners
- School of Chemistry, University of Bristol, Cantock's Close, Bristol, BS8 1TS, UK.,Department of Chemistry, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
| |
Collapse
|