DUDOGNON Yohan 03/26/2015 Bibliography Seminar The synthesis of cyclopropenes and their applications in cycloadditions from 2006 to nowadays Bond lengths (2+1) Cycloaddition (2+2+1) Pauson‐Khand Angles 1,2‐Elimination (3+2+1) Strain energy From other cyclopropenes (2+2) Reactivity (4+2) (3+3) 2 Vinylic nature h C h = 115° of C3 protons 3 3 3 H 1.088 Å Reacts sometimes 1 H like an alkyne 3 H 2 1.296 Å c3C2c1 = 51° H Short bond 2 F. Allen, Tetraheddron, 1982, 38, 645 Vinylic nature h C h = 115° of C3 protons 3 3 3 H 1.088 Å Reacts sometimes 1 H like an alkyne 3 H 2 1.296 Å c3C2c1 = 51° H Short bond 2 F. Allen, Tetraheddron, 1982, 38, 645 Vinylic nature h C h = 115° of C3 protons 3 3 3 H 1.088 Å Reacts sometimes Strain Energy (kcal/mol): 1 H like an alkyne 3 Cyclohexane: 0.1 H 2 1.296 Å Cyclobutane: 26.3 c3C2c1 = 51° H Cyclopropane: 27.5 Short bond Cyclopropene: 54.1 2 F. Allen, Tetraheddron, 1982, 38, 645 Vinylic nature h C h = 115° of C3 protons 3 3 3 H 1.088 Å Reacts sometimes Strain Energy (kcal/mol): 1 H like an alkyne 3 Cyclohexane: 0.1 H 2 1.296 Å Cyclobutane: 26.3 c3C2c1 = 51° H Cyclopropane: 27.5 Short bond Cyclopropene: 54.1 Because the ring is highly strained, cyclopropenes are both difficult to prepare and interesting to study 2 F. Allen, Tetraheddron, 1982, 38, 645 General scheme of all the ways to synthesize cyclopropenes From carbenes and carbenoids (2+1) cycloaddition Si cycloisomerization 1,1-elimination/ of vinyl carbenes 1,2-Si shift 1.3/1.2-elimination X X 4-membered ring contraciton Ring X Y contraction 1.2-elimination Elimination 5-membered ring contraction, extrusion of N2 N X X N Rn 1.3-elimination MG O O 5-membered ring contraction, photochemical rearrangement extrusion of CO2 additions to cyclopropylium salts Rearrangement isomerization and isomerization from other · From other cyclopropenes cycloisomerization 3-membered rings retro-DA and other 3 retrocyclizations M. Rubin, M.Rubina, V. Gevorgyan, Synthesis, 2006, 8, 1221 (2+1) Cycloaddition between alkynes and carbenes or carbenoids 4 IUPAC Nomemclature of cycloaddition 5 Website: http://goldbook.iupac.org/C01496.html IUPAC Nomemclature of cycloaddition Use [x+y] (square brackets) for the number of electrons involved in the transformation Use (x+y) (parenthesis) for the number of atoms involved in the transformation 5 Website: http://goldbook.iupac.org/C01496.html IUPAC Nomemclature of cycloaddition Use [x+y] (square brackets) for the number of electrons involved in the transformation Use (x+y) (parenthesis) for the number of atoms involved in the transformation Example of a 1,3‐dipolar cycloaddition: 5 Website: http://goldbook.iupac.org/C01496.html IUPAC Nomemclature of cycloaddition Use [x+y] (square brackets) for the number of electrons involved in the transformation Use (x+y) (parenthesis) for the number of atoms involved in the transformation Example of a 1,3‐dipolar cycloaddition: 1,3‐dipolar cycloadditions can be called: (3+2) cycloaddition (number of atoms) or [4+2] cycloaddition (number of electrons) 5 Website: http://goldbook.iupac.org/C01496.html (2+1) Cycloaddition between alkynes and carbenes or carbenoids 4 (2+1) Cycloaddition between alkynes and carbenes or carbenoids General scheme 4 (2+1) Cycloaddition between alkynes and carbenes or carbenoids General scheme Two types of cycloadditions 4 (2+1) Cycloaddition between alkynes and carbenes or carbenoids General scheme Two types of cycloadditions Transition‐Metal‐Catalysed (carbenoids): Rh Ag Ir Co Cu Zn 4 (2+1) Cycloaddition between alkynes and carbenes or carbenoids General scheme Two types of cycloadditions Transition‐Metal‐Catalysed (carbenoids): Rh Ag Ir Co Cu Zn Transition‐Metal‐Free: In situ generated carbenes 4 Transition‐Metal‐Catalysed cycloadditions First general method for cyclopropenation that tolerates ß‐hydrogens Highly substituted cyclopropenes bearing an ester and different aromatics 6 P. Panne, J. Fox, J. Am. Chem. Soc., 2006, 129, 22 Transition‐Metal‐Catalysed cycloadditions First general method for cyclopropenation that tolerates ß‐hydrogens Highly substituted cyclopropenes bearing an ester and different aromatics Creation of distinct types of complex molecules from identical starting materials based solely on catalyst selection 6 P. Panne, J. Fox, J. Am. Chem. Soc., 2006, 129, 22 Transition‐Metal‐Catalysed cycloadditions 7 J.Briones, H. Davies, Org. Let., 2011, 13, 3984 Transition‐Metal‐Catalysed cycloadditions Silver triflate: efficient for the cyclopropenation of internal alkynes using donor‐/‐ acceptor‐substituted diazo compounds as carbenoid precursors. 7 J.Briones, H. Davies, Org. Let., 2011, 13, 3984 Transition‐Metal‐Catalysed cycloadditions Silver triflate: efficient for the cyclopropenation of internal alkynes using donor‐/‐ acceptor‐substituted diazo compounds as carbenoid precursors. Highly substituted cyclopropenes 7 J.Briones, H. Davies, Org. Let., 2011, 13, 3984 Transition‐Metal‐Catalysed cycloadditions Silver triflate: efficient for the cyclopropenation of internal alkynes using donor‐/‐ acceptor‐substituted diazo compounds as carbenoid precursors. Highly substituted cyclopropenes Cannot be synthesized via Rh(II)‐catalysed carbenoid chemistry (steric hindrance) 7 J.Briones, H. Davies, Org. Let., 2011, 13, 3984 Transition‐Metal‐Catalysed cycloadditions Et2Zn CH2I2 (stoechiometric) R R R R R R R R not formed Simmons‐Smith does not work with alkynes 8 M. Gonzalez, L. Lopez, R. Vincente, Org. Let., 2014, 16, 5780 Transition‐Metal‐Catalysed cycloadditions 1 R R2 R2 O R3 ZnCl2 R1 Et2Zn CH2I2 O (catalytic) [Zn] (stoechiometric) 3 R Proposed R R R R' intermediate R R R (This work) 3 Fu R Fu R3 R R R R not formed R R R' Simmons‐Smith does not work with alkynes First zinc‐catalyzed cyclopropenation Inexpensive and less toxic catalyst Mild conditions (25 °C, DCM, 0.5‐7 h) 8 M. Gonzalez, L. Lopez, R. Vincente, Org. Let., 2014, 16, 5780 Transition‐Metal‐Catalysed cycloadditions [Rh2(esp)2](2.5mol%) CF3 NH3Cl NaNO2 (2.4 equiv) R1 2 R 1 2 CF3 R R 2eq H2SO4 (10 mol%) NaOAc (20 mol%) 7 examples 67 to 78 % yield H2O, rt, 14 h Highly useful subunits (CF3 groups and functionalisable cyclopropenes) 9 B. Morandi, E. Carreira, Angew. Chem., 2010, 49, 4294 Transition‐Metal‐Catalysed cycloadditions [Rh2(esp)2](2.5mol%) CF3 NH3Cl NaNO2 (2.4 equiv) R1 2 R 1 2 CF3 R R 2eq H2SO4 (10 mol%) NaOAc (20 mol%) 7 examples 67 to 78 % yield H2O, rt, 14 h Highly useful subunits (CF3 groups and functionalisable cyclopropenes) First cyclopropenation of alkynes with trifluoromethyldiazomethane 9 B. Morandi, E. Carreira, Angew. Chem., 2010, 49, 4294 Transition‐Metal‐Catalysed cycloadditions [Rh2(esp)2](2.5mol%) CF3 NH3Cl NaNO2 (2.4 equiv) R1 2 R 1 2 CF3 R R 2eq H2SO4 (10 mol%) NaOAc (20 mol%) 7 examples 67 to 78 % yield H2O, rt, 14 h Highly useful subunits (CF3 groups and functionalisable cyclopropenes) First cyclopropenation of alkynes with trifluoromethyldiazomethane Key: identification of a robust catalyst to support harsh conditions 9 B. Morandi, E. Carreira, Angew. Chem., 2010, 49, 4294 Enantioselective Transition‐Metal‐Catalysed cycloadditions Ar2 2 -45 °C, pentane, 2 h Ar CO2Me N2 Ar1 CO Me 2 Ar1 H O Rh N O Rh 13 examples SO C H C H 24-67% yield 2 6 4 12 25 66-96% ee 4 [Rh2(S-DOSP)4] [Rh2(S‐DOSP)4] effective catalyst for highly enantioselective cyclopropenation 10 J. Briones, J. Hansen, K. Hardcastle, J. Autschbach, H. Davies; J. Am. Chem. Soc., 2010, 132, 17211 Enantioselective Transition‐Metal‐Catalysed cycloadditions Ar2 2 -45 °C, pentane, 2 h Ar CO2Me N2 Ar1 CO Me 2 Ar1 H O Rh N O Rh 13 examples SO C H C H 24-67% yield 2 6 4 12 25 66-96% ee 4 [Rh2(S-DOSP)4] [Rh2(S‐DOSP)4] effective catalyst for highly High enantioselectivity governed by: enantioselective cyclopropenation Specific orientation of the approach of the alkyne due to hydrogen bonding 10 J. Briones, J. Hansen, K. Hardcastle, J. Autschbach, H. Davies; J. Am. Chem. Soc., 2010, 132, 17211 Enantioselective Transition‐Metal‐Catalysed cycloadditions O R2 O R1O R1O P CN [Rh2(S-IBAZ)4](1mol%) P CN R1O R1O 1 N2 R = iPr Toluene (degassed) R2 rt, 20 h 5 examples Rh O 73-95% yield Isosteres 91-98% ee Rh N 2 O CO2i-Bu R 4 O C CN [Rh2(S-IBAZ)4](1mol%) R1O [Rh2(S-IBAZ)4] 1 C CN R O R2 N2 Toluene/Mesitylene (4:1) R1 = tBu 2 examples 0° C to rt, 20 h 88-99% yield 83-93% ee First catalyticasymmetricroute to diacceptor cyclopropenylphosphonates 11 V. Lindsay, D. Fiset, P. Gritsch, S. Azzi, A. Charrette, J. Am. Chem. Soc., 2013, 135, 1463 Enantioselective Transition‐Metal‐Catalysed cycloadditions O R2 O R1O R1O P CN [Rh2(S-IBAZ)4](1mol%) P CN R1O R1O 1 N2 R = iPr Toluene (degassed) R2 rt, 20 h 5 examples Rh O 73-95% yield Isosteres 91-98% ee Rh N 2 O CO2i-Bu R 4 O C CN [Rh2(S-IBAZ)4](1mol%) R1O [Rh2(S-IBAZ)4] 1 C CN R O R2 N2 Toluene/Mesitylene (4:1) R1 = tBu 2 examples 0° C to rt, 20 h 88-99% yield 83-93% ee First catalyticasymmetricroute to diacceptor cyclopropenylphosphonates Takes advantages of the particuliar reactivity of the cyanocarbenes 11 V. Lindsay, D. Fiset, P. Gritsch, S. Azzi, A. Charrette, J. Am. Chem. Soc., 2013, 135, 1463 Enantioselective Transition‐Metal‐Catalysed cycloadditions O R2 O R1O R1O P CN [Rh2(S-IBAZ)4](1mol%) P CN R1O R1O 1 N2 R = iPr Toluene (degassed) R2 rt, 20 h 5 examples Rh O 73-95% yield Isosteres 91-98% ee Rh N 2 O CO2i-Bu R 4 O C CN [Rh2(S-IBAZ)4](1mol%) R1O [Rh2(S-IBAZ)4] 1 C CN R O R2 N2 Toluene/Mesitylene (4:1) R1 = tBu 2 examples 0° C to rt, 20 h 88-99% yield 83-93% ee First catalyticasymmetricroute to diacceptor cyclopropenylphosphonates Takes advantages of the particuliar reactivity of the cyanocarbenes Scope extented to ester cyclopropenes and substituted allenes 11 V.