Highly enantioselective access to diketopiperazines via cinchona alkaloid catalyzed Michael additions
Cabanillas, Alejandro; Davies, Christopher D.; Male, Louise; Simpkins, Nigel S.; Chem. Sci. 6 (2015) 1350–; doi:10.1039/C4SC03218G

data_1518344
_publ_section_title
;
 Highly enantioselective access to diketopiperazines via cinchona alkaloid
 catalyzed Michael additions
;
_journal_issue                   2
_journal_name_full               'Chem. Sci.'
_journal_page_first              1350
_journal_paper_doi               10.1039/C4SC03218G
_journal_volume                  6
_journal_year                    2015
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C24 H26 N2 O5'
_chemical_formula_sum            'C24 H26 N2 O5'
_chemical_formula_weight         422.47
_chemical_name_systematic
;
1,4-dibenzyl-6-(2-(2-methyl-1,3-dioxolan-2-yl)ethyl)piperazine-2,3,5-trione
;
_space_group_crystal_system      triclinic
_space_group_IT_number           1
_space_group_name_Hall           'P 1'
_space_group_name_H-M_alt        'P 1'
_symmetry_space_group_name_Hall  'P 1'
_symmetry_space_group_name_H-M   'P 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             2014-08-01
_audit_creation_method
;
Olex2 1.2
(compiled 2014.07.22 svn.r2960 for OlexSys, GUI svn.r4862)
;
_audit_update_record
;
2014-08-01 deposited with the CCDC.
2014-11-28 downloaded from the CCDC.
;
_cell_angle_alpha                100.7552(12)
_cell_angle_beta                 92.7028(13)
_cell_angle_gamma                95.0674(14)
_cell_formula_units_Z            2
_cell_length_a                   6.25441(12)
_cell_length_b                   12.5920(2)
_cell_length_c                   13.61853(18)
_cell_measurement_reflns_used    24970
_cell_measurement_temperature    100.01(10)
_cell_measurement_theta_max      73.4750
_cell_measurement_theta_min      3.2870
_cell_volume                     1047.35(3)
_computing_cell_refinement
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
;
_computing_data_collection
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
;
_computing_data_reduction
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
;
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2008)'
_computing_structure_solution    'ShelXS (Sheldrick, 2008)'
_diffrn_ambient_temperature      100.01(10)
_diffrn_detector_area_resol_mean 5.1768
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.993
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Atlas'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0275
_diffrn_reflns_av_unetI/netI     0.0191
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.993
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            37897
_diffrn_reflns_point_group_measured_fraction_full 0.959
_diffrn_reflns_point_group_measured_fraction_max 0.942
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         73.671
_diffrn_reflns_theta_min         3.310
_diffrn_source                   'SuperNova (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.772
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.76517
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.36.28 (release 01-02-2013 CrysAlis171 .NET)
(compiled Feb  1 2013,16:14:44)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.340
_exptl_crystal_description       Lath
_exptl_crystal_F_000             448
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.07
_exptl_crystal_size_min          0.035
_refine_diff_density_max         0.315
_refine_diff_density_min         -0.200
_refine_diff_density_rms         0.035
_refine_ls_abs_structure_details
;
 Flack x determined using 3577 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons and Flack (2004), Acta Cryst. A60, s61).
;
_refine_ls_abs_structure_Flack   -0.03(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.042
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     561
_refine_ls_number_reflns         7953
_refine_ls_number_restraints     3
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.0314
_refine_ls_R_factor_gt           0.0302
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0440P)^2^+0.2291P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0778
_refine_ls_wR_factor_ref         0.0785
_reflns_Friedel_coverage         0.898
_reflns_Friedel_fraction_full    0.918
_reflns_Friedel_fraction_max     0.891
_reflns_number_gt                7728
_reflns_number_total             7953
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c4sc03218g2.cif
_cod_data_source_block           Ketal_Derivative_of_6h
_cod_depositor_comments
'Adding full bibliography for 1518342--1518345.cif.'
_cod_original_cell_volume        1047.36(3)
_cod_database_code               1518344
_shelxl_version_number           2013-4
_shelx_estimated_absorpt_t_max   0.973
_shelx_estimated_absorpt_t_min   0.813
_olex2_refinement_description
;
1. Others
 Fixed Uiso: H6(0.026) H7A(0.029) H7B(0.029) H8A(0.029) H8B(0.029) H11A(0.042)
 H11B(0.042) H12A(0.042) H12B(0.042) H14A(0.052) H14B(0.052) H14C(0.052)
 H15A(0.028) H15B(0.028) H17(0.027) H18(0.031) H19(0.037) H20(0.041) H21(0.034)
 H22A(0.029) H22B(0.029) H24(0.037) H25(0.042) H26(0.036) H27(0.037) H28(0.032)
 H106(0.025) H10A(0.028) H10B(0.028) H10C(0.029) H10D(0.029) H11C(0.051)
 H11D(0.051) H11E(0.046) H11F(0.046) H11G(0.045) H11H(0.045) H11I(0.045)
 H11J(0.028) H11K(0.028) H117(0.029) H118(0.034) H119(0.041) H120(0.044)
 H121(0.037) H12C(0.03) H12D(0.03) H124(0.035) H125(0.037) H126(0.035)
 H127(0.037) H128(0.032)
 Fixed X: H6(0.7158) H7A(0.9871) H7B(0.8849) H8A(0.5565) H8B(0.6718)
 H11A(0.541) H11B(0.6213) H12A(0.4432) H12B(0.3388) H14A(1.0958) H14B(0.9516)
 H14C(1.0117) H15A(1.1352) H15B(1.1843) H17(0.7004) H18(0.5469) H19(0.716)
 H20(1.0355) H21(1.1863) H22A(0.2774) H22B(0.4377) H24(0.0843) H25(0.0182)
 H26(0.2602) H27(0.5718) H28(0.6425) H106(0.2871) H10A(0.6247) H10B(0.5223)
 H10C(0.3742) H10D(0.2401) H11C(1.0001) H11D(0.882) H11E(0.7487) H11F(0.7588)
 H11G(0.4199) H11H(0.2839) H11I(0.523) H11J(0.6584) H11K(0.7023) H117(0.1755)
 H118(-0.0142) H119(0.1461) H120(0.5021) H121(0.6907) H12C(-0.1342)
 H12D(0.0162) H124(0.2995) H125(0.3025) H126(0.0234) H127(-0.2598) H128(-0.2677)
 Fixed Y: H6(0.8907) H7A(0.7919) H7B(0.6835) H8A(0.6981) H8B(0.8008)
 H11A(0.5001) H11B(0.4141) H12A(0.4858) H12B(0.5608) H14A(0.7124) H14B(0.7729)
 H14C(0.6528) H15A(0.9446) H15B(0.9552) H17(1.0008) H18(1.1657) H19(1.3196)
 H20(1.3087) H21(1.1431) H22A(0.6502) H22B(0.5883) H24(0.5478) H25(0.3897)
 H26(0.2576) H27(0.2861) H28(0.445) H106(0.7658) H10A(0.8747) H10B(0.9788)
 H10C(0.8555) H10D(0.9466) H11C(1.0868) H11D(1.1286) H11E(1.2357) H11F(1.1473)
 H11G(0.9468) H11H(1.0434) H11I(1.0702) H11J(0.7117) H11K(0.7105) H117(0.6506)
 H118(0.4787) H119(0.3236) H120(0.3409) H121(0.5115) H12C(0.9884) H12D(1.0447)
 H124(1.1286) H125(1.2962) H126(1.4055) H127(1.3449) H128(1.1766)
 Fixed Z: H6(0.3949) H7A(0.3085) H7B(0.3405) H8A(0.2472) H8B(0.2104)
 H11A(0.2194) H11B(0.1291) H12A(0.0159) H12B(0.1066) H14A(0.1523) H14B(0.0842)
 H14C(0.0412) H15A(0.4353) H15B(0.5533) H17(0.5887) H18(0.6203) H19(0.5736)
 H20(0.4917) H21(0.4569) H22A(0.5254) H22B(0.5846) H24(0.38) H25(0.257)
 H26(0.2437) H27(0.3484) H28(0.469) H106(0.9423) H10A(1.0103) H10B(0.984)
 H10C(1.1281) H10D(1.0943) H11C(1.1692) H11D(1.2699) H11E(1.1735) H11F(1.0722)
 H11G(1.3039) H11H(1.284) H11I(1.3351) H11J(0.8968) H11K(0.7819) H117(0.7491)
 H118(0.7018) H119(0.7234) H120(0.7899) H121(0.8392) H12C(0.8114) H12D(0.7402)
 H124(0.9593) H125(1.0673) H126(1.0545) H127(0.9339) H128(0.8279)
;
_olex2_submission_special_instructions 'No special instructions were received'