Tunable regioselectivity for C-H alkynylation of weakly coordinating amides that tolerated strongly coordinating heterocycles.
Liu, Bifu; Zhang, Qiaoya; Zhang, Jun; Huang, Aidong; Zhong, Hulin; Feng, Kejun; Gao, Yang; Huo, Yanping; Chen, Qian; Li, Xianwei; Chemical communications (Cambridge, England) 62 (2026) 6373–6377; doi:10.1039/d6cc00867d

data_7135440
_publ_section_title
;
 Tunable regioselectivity for C-H alkynylation of weakly coordinating
 amides that tolerated strongly coordinating heterocycles.
;
_journal_issue                   23
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              6373
_journal_page_last               6377
_journal_paper_doi               10.1039/d6cc00867d
_journal_volume                  62
_journal_year                    2026
_chemical_formula_moiety         'C16 H19 N O4 S'
_chemical_formula_sum            'C16 H19 N O4 S'
_chemical_formula_weight         321.38
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2026-01-22
_audit_creation_method
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7314)
;
_audit_update_record
;
2026-01-31 deposited with the CCDC.	2026-02-20 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 95.639(4)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   6.9274(5)
_cell_length_b                   21.8077(16)
_cell_length_c                   20.0653(15)
_cell_measurement_reflns_used    7205
_cell_measurement_temperature    170
_cell_measurement_theta_max      63.77
_cell_measurement_theta_min      4.05
_cell_volume                     3016.6(4)
_computing_cell_refinement       'SAINT V8.41 (?, 2016)'
_computing_data_reduction        'SAINT V8.41 (?, 2016)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      170
_diffrn_measured_fraction_theta_full 0.981
_diffrn_measured_fraction_theta_max 0.981
_diffrn_measurement_device_type  'D8 VENTURE'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0866
_diffrn_reflns_av_unetI/netI     0.0587
_diffrn_reflns_Laue_measured_fraction_full 0.981
_diffrn_reflns_Laue_measured_fraction_max 0.981
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       25
_diffrn_reflns_limit_k_min       -25
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            21579
_diffrn_reflns_point_group_measured_fraction_full 0.981
_diffrn_reflns_point_group_measured_fraction_max 0.981
_diffrn_reflns_theta_full        63.864
_diffrn_reflns_theta_max         63.864
_diffrn_reflns_theta_min         3.001
_diffrn_source_current           1.2
_diffrn_source_power             0.06
_diffrn_source_voltage           50.0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    2.071
_exptl_absorpt_correction_T_max  0.7524
_exptl_absorpt_correction_T_min  0.6180
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1418 before and 0.0906 after correction.
The Ratio of minimum to maximum transmission is 0.8214.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.415
_exptl_crystal_description       needle
_exptl_crystal_F_000             1360
_exptl_crystal_size_max          0.11
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.441
_refine_diff_density_min         -0.521
_refine_diff_density_rms         0.083
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.089
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     401
_refine_ls_number_reflns         4879
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.089
_refine_ls_R_factor_all          0.0804
_refine_ls_R_factor_gt           0.0623
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0681P)^2^+4.9711P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1534
_refine_ls_wR_factor_ref         0.1677
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3825
_reflns_number_total             4879
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d6cc00867d2.cif
_cod_data_source_block           cs6_0m
_cod_depositor_comments          'Adding full bibliography for 7135440.cif.'
_cod_database_code               7135440
_shelx_shelxl_version_number     2019/3
_shelx_estimated_absorpt_t_max   0.960
_shelx_estimated_absorpt_t_min   0.804
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups, All O(H) groups
2.a Secondary CH2 refined with riding coordinates:
 C19(H19A,H19B), C8(H8A,H8B), C7(H7A,H7B), C11(H11A,H11B), C23(H23A,H23B),
 C22(H22A,H22B), C10(H10A,H10B), C9(H9A,H9B), C20(H20A,H20B), C21(H21A,H21B)
2.b Aromatic/amide H refined with riding coordinates:
 C4(H4), C15(H15), C28(H28), C14(H14), C31(H31), C24(H24), C30(H30), C12(H12),
 C29(H29), C13(H13)
2.c Idealised Me refined as rotating group:
 C16(H16A,H16B,H16C), C32(H32A,H32B,H32C)
2.d Idealised tetrahedral OH refined as rotating group:
 O1(H1), O5(H5)
;
_olex2_submission_special_instructions 'No special instructions were received'