Biginelli Dihydropyrimidines: A Tunable Class of Alkyl Radical Precursors
Ratnam, Shahilan; Unone, Shreya; Alia, Nabeel; Hafeneger, Enyu Denny; Janssen-Müller, Daniel; Chemical Science  (2026) –; doi:10.1039/D6SC00376A

data_1576878
_publ_section_title
;
 Biginelli dihydropyrimidines: a tunable class of alkyl radical
 precursors.
;
_journal_issue                   18
_journal_name_full               'Chemical science'
_journal_page_first              8998
_journal_page_last               9005
_journal_paper_doi               10.1039/d6sc00376a
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety         'C15 H24 N2 O2 S'
_chemical_formula_sum            'C15 H24 N2 O2 S'
_chemical_formula_weight         296.436
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_symmetry_Int_Tables_number      14
_atom_sites_solution_primary     dual
_audit_creation_date             2023-08-16
_audit_creation_method
;FinalCif V123 by Daniel Kratzert, Freiburg 2023, 
https://dkratzert.de/finalcif.html
;
_audit_update_record
;
2024-03-08 deposited with the CCDC.	2026-03-13 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 92.322(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   13.3817(7)
_cell_length_b                   9.0674(5)
_cell_length_c                   12.4298(8)
_cell_measurement_reflns_used    9639
_cell_measurement_temperature    100.00
_cell_measurement_theta_max      33.151
_cell_measurement_theta_min      2.715
_cell_volume                     1506.96(15)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_collection
'Bruker BIS V6.2.15/2021-03-16 && APEX4 2022.1-1'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'olex2.refine 1.5 (Bourhis et al., 2015)'
_computing_structure_solution    'XT  (Sheldrick, 2015)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100.00
_diffrn_detector                 CPAD
_diffrn_detector_area_resol_mean 7.41
_diffrn_detector_type            'Bruker PHOTON III'
_diffrn_measured_fraction_theta_full 0.9996
_diffrn_measured_fraction_theta_max 0.9527
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'Bruker D8 VENTURE dual wavelength Mo/Cu'
_diffrn_measurement_method       '\w and \f scans'
_diffrn_measurement_specimen_support 'MiTeGen micromount'
_diffrn_radiation_monochromator  'mirror optics'
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0358
_diffrn_reflns_av_unetI/netI     0.0169
_diffrn_reflns_Laue_measured_fraction_full 0.9996
_diffrn_reflns_Laue_measured_fraction_max 0.9527
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            53044
_diffrn_reflns_point_group_measured_fraction_full 0.9996
_diffrn_reflns_point_group_measured_fraction_max 0.9527
_diffrn_reflns_theta_full        25.2417
_diffrn_reflns_theta_max         33.12
_diffrn_reflns_theta_min         2.71
_diffrn_source                   'microfocus sealed X-ray tube'
_diffrn_source_current           1.0
_diffrn_source_power             0.05
_diffrn_source_type              'Incoatec I\ms'
_diffrn_source_voltage           50.0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.219
_exptl_absorpt_correction_T_max  1.0000
_exptl_absorpt_correction_T_min  0.7542
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1592 before and 0.0474 after correction.
The Ratio of minimum to maximum transmission is 0.7542.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.307
_exptl_crystal_description       block
_exptl_crystal_F_000             640.849
_exptl_crystal_recrystallization_method
'from a mixture of ethyl acetate and pentane.'
_exptl_crystal_size_max          0.594
_exptl_crystal_size_mid          0.226
_exptl_crystal_size_min          0.102
_refine_diff_density_max         0.1678
_refine_diff_density_min         -0.1356
_refine_diff_density_rms         0.0297
_refine_ls_d_res_high            0.6504
_refine_ls_d_res_low             7.5045
_refine_ls_goodness_of_fit_ref   1.1160
_refine_ls_hydrogen_treatment    refall
_refine_ls_matrix_type           full
_refine_ls_number_constraints    0
_refine_ls_number_parameters     397
_refine_ls_number_reflns         5461
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.1160
_refine_ls_R_factor_all          0.0162
_refine_ls_R_factor_gt           0.0144
_refine_ls_shift/su_max          -0.0002
_refine_ls_shift/su_mean         0.0000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0141P)^2^+0.0246P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0325
_refine_ls_wR_factor_ref         0.0334
_reflns_Friedel_coverage         0.0
_reflns_limit_h_max              20
_reflns_limit_h_min              -20
_reflns_limit_k_max              13
_reflns_limit_k_min              0
_reflns_limit_l_max              18
_reflns_limit_l_min              0
_reflns_number_gt                5179
_reflns_number_total             5461
_reflns_threshold_expression     I>=2u(I)
_cod_data_source_file            d6sc00376a2.cif
_cod_data_source_block           2076_P21c
_cod_depositor_comments
'Adding full bibliography for 1576876--1576878.cif.'
_cod_database_code               1576878
_olex2_refine_details
;
Refinement using NoSpherA2, an implementation of
NOn-SPHERical Atom-form-factors in Olex2.
Please cite:
F. Kleemiss et al. Chem. Sci. DOI 10.1039/D0SC05526C - 2021
NoSpherA2 implementation of HAR makes use of
tailor-made aspherical atomic form factors calculated
on-the-fly from a Hirshfeld-partitioned electron density (ED) - not from
spherical-atom form factors.

The ED is calculated from a gaussian basis set single determinant SCF
wavefunction - either Hartree-Fock or DFT using selected funtionals
 - for a fragment of the crystal.
This fragment can be embedded in an electrostatic crystal field by employing cluster charges
or modelled using implicit solvation models, depending on the software used.
The following options were used:
   SOFTWARE:       ORCA 5.0
   PARTITIONING:   NoSpherA2
   INT ACCURACY:   Normal
   METHOD:         R2SCAN
   BASIS SET:      def2-TZVP
   CHARGE:         0
   MULTIPLICITY:   1
   DATE:           2023-08-16_09-10-10
;
_olex2_refinement_description
;
1. 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
;
_olex2_submission_special_instructions 'No special instructions were received'
_diffrn_measurement_ambient_temperature_device_make 'Oxford Cryostream 800'