Remote stereocontrol is a difficult topic in current organic synthesis. We have developed a highly diastereoselective 1,4-asymmetric induction using a cobalt alkyne complex. This is the first example of using a cobalt alkyne complex for a stereoselective reaction via 1,4-chelation. Both anti and syn isomers were stereoselectively synthesized using two different methods.

The cross-in-square was one of the most common church forms in the middle Byzantine period (9th-12th centuries penetrate inner walls.

This paper looks at changes over time in the construction procedure of ceilings of cross-in-square churches, one of the most common architecture in the Middle Byzantine period (9th-12th centuries), focusing on the three-dimensional characteristics of all churches within

Abstract. The use of Structure-from-Motion algorithms is a common practice to obtain a rapid photogrammetric reconstruction. However, the performance of these algorithms is limited by the fact that in some conditions the resulting point clouds present low density. This is the case when processing materials from historical archives, such as photographs and videos, which generates only sparse point clouds due to the lack of necessary information in the photogrammetric reconstruction. This paper explores ways to improve the performance of open source SfM algorithms in order to guarantee the presence of strategic feature points in the resulting point cloud, even if sparse. To reach this objective, a photogrammetric workflow is proposed to process historical images. The first part of the workflow presents a method that allows the manual selection of feature points during the photogrammetric process. The second part evaluates the metric quality of the reconstruction on the basis of a comparison with a point cloud that has a different density from the sparse point cloud. The workflow was applied to two different case studies. Transformations of wall paintings of the Karanlık church in Cappadocia were analysed thanks to the comparison of 3D model resulting from archive photographs and a recent survey. Then a comparison was performed between the state of the Komise building in Japan, before and after restoration. The findings show that the method applied allows the metric scale and evaluation of the model also in bad condition and when only low-density point clouds are available. Moreover, this tool should be of great use for both art and architecture historians and geomatics experts, to study the evolution of Cultural Heritage.

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