Diels-Alder Exo Selectivity in Terminal-Substituted Dienes and Dienophiles: Experimental Discoveries and Computational Explanations
Yu-hong Lam; Paul Ha-Yeon Cheong; José M. Blasco Mata; Steven J. Stanway; Véronique Gouverneur; K. N. Houk; Journal of the American Chemical Society 131 (2009) 1947–1957; doi:10.1021/ja8079548

data_4103885
_publ_section_title
;
 Diels-Alder Exo Selectivity in Terminal-Substituted Dienes and
 Dienophiles: Experimental Discoveries and Computational Explanations
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              1947
_journal_page_last               1957
_journal_paper_doi               10.1021/ja8079548
_journal_volume                  131
_journal_year                    2009
_chemical_absolute_configuration syn
_chemical_compound_source
;
synthesis as described
;
_chemical_formula_moiety         ' C29 H37 N O3 Si '
_chemical_formula_sum            'C29 H37 N O3 Si'
_chemical_formula_weight         475.70
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.3906(2)
_cell_length_b                   10.7093(2)
_cell_length_c                   39.9227(6)
_cell_measurement_reflns_used    15497
_cell_measurement_temperature    150
_cell_measurement_theta_max      28
_cell_measurement_theta_min      5
_cell_volume                     2732.26(11)
_computing_cell_refinement
; 
KappaCCD software 'DENZO' (Otwinowski & Minor, 1996) 
;
_computing_data_collection
; 
KappaCCD software 'Collect' (Nonius, 2000) 
;
_computing_data_reduction
; 
KappaCCD software 'DENZO' (Otwinowski & Minor, 1996) 
;
_computing_publication_material
; 
CRYSTALS (Watkin et al, 2001) 
;
_computing_structure_refinement
; 
CRYSTALS (Watkin et al, 2001) 
;
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1992)'
_diffrn_ambient_temperature      150
_diffrn_measured_fraction_theta_full 0.989
_diffrn_measured_fraction_theta_max 0.989
_diffrn_measurement_device_type
; 
Nonius KappaCCD 
;
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.041
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       51
_diffrn_reflns_limit_l_min       -51
_diffrn_reflns_number            15497
_diffrn_reflns_theta_full        27.477
_diffrn_reflns_theta_max         27.477
_diffrn_reflns_theta_min         5.107
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.115
_exptl_absorpt_correction_T_max  1.00
_exptl_absorpt_correction_T_min  0.96
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
; 
 Denzo/Scalepack (Otwinowski & Minor, 1996) 
;
_exptl_crystal_colour            ' colourless '
_exptl_crystal_density_diffrn    1.156
_exptl_crystal_description       ' fragment '
_exptl_crystal_F_000             1024
_exptl_crystal_size_max          0.36
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.04
_exptl_crystal_thermal_history
; 
The material was crystallised at ambient temperature. A suitable crystal 
was cooled rapidly to 150K for single-crystal X-ray diffraction analysis. 
;
_refine_diff_density_max         0.38
_refine_diff_density_min         -0.31
_refine_ls_abs_structure_details 'Flack, 2080 Friedel-pairs'
_refine_ls_abs_structure_Flack   -0.06(13)
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.0945
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     308
_refine_ls_number_reflns         4069
_refine_ls_number_restraints     0
_refine_ls_R_factor_all          0.0606
_refine_ls_R_factor_gt           0.0377
_refine_ls_shift/su_max          0.004375
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
 Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982) 
 [weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)] 
 where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax 
 Method = Robust Weighting (Prince, 1982) 
 W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^ 
 A~i~ are: 
 0.519 0.128 0.274 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0592
_refine_ls_wR_factor_gt          0.0411
_refine_ls_wR_factor_ref         0.0411
_reflns_limit_h_max              8
_reflns_limit_h_min              -8
_reflns_limit_k_max              13
_reflns_limit_k_min              0
_reflns_limit_l_max              51
_reflns_limit_l_min              0
_reflns_number_gt                4069
_reflns_number_total             5615
_reflns_threshold_expression     I>3.00u(I)
_cod_data_source_file            ja8079548_si_002.cif
_cod_data_source_block           arc1464
_cod_original_sg_symbol_H-M      'P 21 21 21 '
_cod_original_formula_sum        ' C29 H37 N O3 Si '
_cod_database_code               4103885