An Unexpected Ireland-Claisen Rearrangement Cascade During the Synthesis of the Tricyclic Core of Curcusone C: Mechanistic Elucidation by Trial-and-Error and Automatic Artificial Force-Induced Reaction (AFIR) Computations.
Lee, Chung Whan; Taylor, Buck L. H.; Petrova, Galina P.; Patel, Ashay; Morokuma, Keiji; Houk, K. N.; Stoltz, Brian M.; Journal of the American Chemical Society 141 (2019) 6995–7004; doi:10.1021/jacs.9b01146

data_4128143
_publ_section_title
;
 An Unexpected Ireland-Claisen Rearrangement Cascade During the Synthesis
 of the Tricyclic Core of Curcusone C: Mechanistic Elucidation by
 Trial-and-Error and Automatic Artificial Force-Induced Reaction (AFIR)
 Computations.
;
_journal_issue                   17
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              6995
_journal_page_last               7004
_journal_paper_doi               10.1021/jacs.9b01146
_journal_volume                  141
_journal_year                    2019
_chemical_formula_moiety         'C22 H26 N2 O4 S'
_chemical_formula_sum            'C22 H26 N2 O4 S'
_chemical_formula_weight         414.51
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_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   mixed
_atom_sites_solution_primary     direct
_audit_creation_date             2014-12-11
_audit_creation_method
;
Olex2 1.2
(compiled 2014.11.28 svn.r3106 for OlexSys, GUI svn.r4959),
 SHELXL-2014,
 and manual edit
;
_cell_angle_alpha                90.199(3)
_cell_angle_beta                 93.729(3)
_cell_angle_gamma                90.810(3)
_cell_formula_units_Z            8
_cell_length_a                   19.3346(10)
_cell_length_b                   21.5305(11)
_cell_length_c                   9.9784(5)
_cell_measurement_reflns_used    9895
_cell_measurement_temperature    100
_cell_measurement_theta_max      31.81
_cell_measurement_theta_min      2.18
_cell_volume                     4144.6(4)
_computing_cell_refinement       'SAINT V8.34A (Bruker-AXS, 2007)'
_computing_data_collection       'APEX2 2012.10-0 (Bruker-AXS, 2007)'
_computing_data_reduction        'SAINT V8.34A (Bruker-AXS, 2007)'
_computing_molecular_graphics    'DIAMOND 3 (Crystal Impact, 1999)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL-2014/6 (Sheldrick, 2014)'
_computing_structure_solution    'XT-2014/4 (Sheldrick, 2012)'
_diffrn_ambient_temperature      100
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.928
_diffrn_measurement_device_type  'Bruker KAPPA APEX II ccd'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0867
_diffrn_reflns_av_unetI/netI     0.0718
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.928
_diffrn_reflns_limit_h_max       29
_diffrn_reflns_limit_h_min       -28
_diffrn_reflns_limit_k_max       32
_diffrn_reflns_limit_k_min       -32
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            272986
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.928
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         32.962
_diffrn_reflns_theta_min         2.045
_diffrn_source                   'sealed tube'
_diffrn_source_current           30
_diffrn_source_power             1.5
_diffrn_source_target            Mo
_diffrn_source_voltage           50
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.187
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.8821
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2014/4 (Bruker,2014/4) was used for absorption correction. 
wR2(int) was 0.0757 before and 0.0668 after correction. The Ratio 
of minimum to maximum transmission is 0.8821. The \l/2 correction 
factor is 0.00150.'
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.329
_exptl_crystal_description       plate
_exptl_crystal_F_000             1760
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.33
_exptl_crystal_size_min          0.10
_refine_diff_density_max         3.274
_refine_diff_density_min         -1.435
_refine_diff_density_rms         0.134
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.037
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     1054
_refine_ls_number_reflns         29250
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.037
_refine_ls_R_factor_all          0.1406
_refine_ls_R_factor_gt           0.0907
_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^)+(0.1351P)^2^+8.1742P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2272
_refine_ls_wR_factor_ref         0.2638
_reflns_Friedel_coverage         0.000
_reflns_number_gt                19755
_reflns_number_total             29250
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja9b01146_si_003.cif
_cod_data_source_block           cwl102
_cod_database_code               4128143
_shelxl_version_number           2014/6
_shelx_estimated_absorpt_t_max   0.982
_shelx_estimated_absorpt_t_min   0.937
_olex2_refinement_description
;
1. Twinned data refinement
 Scales: 0.8591(9) 0.1409(9)
2. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups, All N(H) groups
 At 1.5 times of:
  All C(H,H,H) groups
3.a Riding coordinates:
 N2(H2), N2B(H2B), N2C(H2C), N2D(H2D)
3.b Ternary CH refined with riding coordinates:
 C2(H2A), C5(H5), C2B(H2BA), C5B(H5B), C2C(H2CA), C5C(H5C), C2D(H2DA), C5D(H5D)
3.c Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C4(H4A,H4B), C19(H19A,H19B), C20(H20A,H20B), C21(H21A,H21B),
 C22(H22A,H22B), C3B(H3BA,H3BB), C4B(H4BA,H4BB), C19B(H19C,H19D), C20B(H20C,
 H20D), C21B(H21C,H21D), C22B(H22C,H22D), C3C(H3CA,H3CB), C4C(H4CA,H4CB),
 C19C(H19E,H19F), C20C(H20E,H20F), C21C(H21E,H21F), C22C(H22E,H22F), C3D(H3DA,
 H3DB), C4D(H4DA,H4DB), C19D(H19G,H19H), C20D(H20G,H20H), C21D(H21G,H21H),
 C22D(H22G,H22H)
3.d Aromatic/amide H refined with riding coordinates:
 C11(H11), C12(H12), C14(H14), C15(H15), C18(H18), C11B(H11B), C12B(H12B),
 C14B(H14B), C15B(H15B), C18B(H18B), C11C(H11C), C12C(H12C), C14C(H14C),
 C15C(H15C), C18C(H18C), C11D(H11D), C12D(H12D), C14D(H14D), C15D(H15D),
 C18D(H18D)
3.e Idealised Me refined as rotating group:
 C9(H9A,H9B,H9C), C16(H16A,H16B,H16C), C9B(H9BA,H9BB,H9BC), C16B(H16D,H16E,
 H16F), C9C(H9CA,H9CB,H9CC), C16C(H16G,H16H,H16I), C9D(H9DA,H9DB,H9DC),
 C16D(H16J,H16K,H16L)
;
_olex2_submission_special_instructions 'No special instructions were received'