Access to α,α-Disubstituted Disilylated Amino Acids and Their Use in Solid-Phase Peptide Synthesis.
Fanelli, Roberto; Salah, Khoubaib Ben Haj; Inguimbert, Nicolas; Didierjean, Claude; Martinez, Jean; Cavelier, Florine; Organic letters 17 (2015) 4498–4501; doi:10.1021/acs.orglett.5b02175

data_1530387
_publ_section_title
;
 Access to \a,\a-Disubstituted Disilylated Amino Acids and Their Use in
 Solid-Phase Peptide Synthesis.
;
_journal_issue                   18
_journal_name_full               'Organic letters'
_journal_page_first              4498
_journal_page_last               4501
_journal_paper_doi               10.1021/acs.orglett.5b02175
_journal_volume                  17
_journal_year                    2015
_chemical_absolute_configuration syn
_chemical_formula_sum            'C32 H59 N O4 Si2'
_chemical_formula_weight         577.98
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_Int_Tables_number      4
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_atom_sites_solution_hydrogens   geom
_audit_creation_date             2015-07-06T10:31:52-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_cell_angle_alpha                90
_cell_angle_beta                 92.581(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   16.472(2)
_cell_length_b                   18.5630(4)
_cell_length_c                   11.996(2)
_cell_measurement_temperature    100(2)
_cell_volume                     3664.3(8)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 1
_diffrn_measured_fraction_theta_max 0.98
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Atlas'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_source         'SuperNova (Cu) X-ray Source'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0657
_diffrn_reflns_av_unetI/netI     0.0596
_diffrn_reflns_Laue_measured_fraction_full 1
_diffrn_reflns_Laue_measured_fraction_max 0.98
_diffrn_reflns_limit_h_max       20
_diffrn_reflns_limit_h_min       -20
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            43981
_diffrn_reflns_point_group_measured_fraction_full 1
_diffrn_reflns_point_group_measured_fraction_max 0.98
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         77.72
_diffrn_reflns_theta_min         3.589
_exptl_absorpt_coefficient_mu    1.118
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.71997
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.31 (release 14-01-2014 CrysAlis171 .NET)
(compiled Jan 14 2014,18:38:18)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
Final absorption correction factors: Amin= 0.8536 and Amax= 1.1856.
;
_exptl_crystal_density_diffrn    1.048
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             1272
_exptl_crystal_size_max          0.32
_exptl_crystal_size_mid          0.142
_exptl_crystal_size_min          0.077
_refine_diff_density_max         0.726
_refine_diff_density_min         -0.319
_refine_diff_density_rms         0.063
_refine_ls_abs_structure_details
;
 Refined as an inversion twin.
;
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.033
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     704
_refine_ls_number_reflns         15195
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.033
_refine_ls_R_factor_all          0.091
_refine_ls_R_factor_gt           0.0711
_refine_ls_shift/su_max          0
_refine_ls_shift/su_mean         0
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1047P)^2^+2.3548P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1853
_refine_ls_wR_factor_ref         0.2092
_reflns_Friedel_coverage         0.939
_reflns_Friedel_fraction_full    1
_reflns_Friedel_fraction_max     0.98
_reflns_number_gt                12026
_reflns_number_total             15195
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol5b02175_si_002.cif
_cod_data_source_block           fr248
_cod_depositor_comments          'Adding full bibliography for 1530387.cif.'
_cod_original_cell_volume        3664.4(8)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               1530387
_shelx_res_checksum              53691
_shelx_hkl_checksum              35536